Just as much fun as a blind playthrough?

Personally, I'm playing Nioh 2 right now and the game is one of the hardest I've ever played. I'm using a video guide as I play to find Kodama hidden in the levels so I can farm health flasks and EXP more easily with a buff they give. The game is exactly the same, the experience is the same, it's still brutally difficult and I need to still "gid gud" but I thought see the level ahead of time would take the fun out of it but it fact it makes it more fun and I don't have to spend the time wandering around levels looking for these things nor have a fomo that I'm not picking them up. I'm usually against guides unless it's after a playthrough for the platinum but I have to say I'm having just as much fun, if not more playing this way with a slight glimpse into the upcoming level. 

I wouldn't play any souls game this way cause of the level design but for Nioh 2 it works. I'm all for it and may adopt this style of play in future to cut down on time lost or frustrating aspects of a game. All the is different is time is being saved. It's not like it's fun looking for collectibles, hidden secrets or the like. 

I'm similar. When e.g. playing Zelda games I go in as blind as possible. After rolling credits, I know I missed a lot of secrets/content. This is when I pick up a guide or view a playthrough to point me to what I missed.

Yeah, it just depends on what I'm looking up and the game.

I'm playing Diablo 4, and I looked up a guide on a certain build before starting.
So now I have a clear goal and I know how to farm the equipment instead of not having a clue what to aim for, or trying to find items aimlessly for hours.

If I look something up, it's usually things that could cause me to not have fun if I miss it in my playthrough.

If I can’t play and beat the game on my own I’m not sure 1) I deserve to play the game, 2) I have invested enough time to understand the systems and techniques required to play the game or 3) the game isn’t broken, which doesn’t happen for wide releases generally.

The best thing a game can do for me is to make me feel confused and disoriented. It’s why I love the backtracking nature of Metroidvanias. And the feeling of overcoming that difficulty spike, puzzle, or path is half the reason I enjoy playing videogames.

Now I understand people don’t have time for that. This isn’t a condemnation of the way other people play. I have, on occasion, made as small of a Google search as I possibly could to spoil the secret of a game to pass an area that I was stuck on. And almost every time I do, I say to myself, “you’re an idiot.” It’s almost never because the puzzle solution was impossible to solve or the path forward wasn’t marked. I hate that feeling so I put it off as much as I can.

I do think that some people give up way too easily. My girlfriend does this. When you get stuck in a room you need to walk around it a bit, study it, see what sticks out or doesn’t fit. Don’t just look at something that is confusing and say, “since I don’t understand it, it’s not there.” But her stress level doesn’t allow her to take in the room this way. She starts feeling stupid and frustrated and like she isn’t smart enough to play the game. I also understand that emotion and how off putting it can be. I help her get through a lot of those situations and that’s why I’m thankful that guides and walkthroughs exist. They really help open the world of gaming up to people that otherwise might be kept out of the fun for not having the emotional capability of overcoming those frustrations. We are all very different people and that isn’t an indictment of any of us.

But for me, personally, no guides thank you.

Yes, I don't really see a reason for a guide to ruin your playthrough unless you spoil the entire game to yourself.

I didn't play Nioh 2 with a guide, game was too fun for that.

However whenever I want to find a weapon or a hidden boss in Elden Ring or something, I definitely will take a peak at a guide after I feel like I scoured the map already.

It depends, I have three different cases here:

1. When I’m doing chore-like things in a game already, like collecting crafting material, I have no problem using a guide: Stardew Valley, Animal Crossing, Final Fantasy 8, Witcher 3, and Breath of the Wild all have these sorts of crafting segments. And even then, I normally don’t use any kind of a guide until I’ve thoroughly explored the game. But I don’t care too much about that. No problems with guides in this case.

2. But when it comes to adventuring and walkthroughs, it’s like using a fork to eat skittles - it turns a fun and delightful experience into a massive chore. This typically ruins games for me, and I’ll lose interest and stop playing a game shortly after I have to use a walkthrough. Examples include the pre-BotW Zelda games. These are typically easy games, but then they stick hidden keys, switches, or even puzzles, you need to complete in order to progress the game. This more or less ruined Ocarina of Time for me and, while I finished it, it was the only 3D Zelda game finished until Breath of the Wild. Metroid Prime was much worse because you could miss one necessary scan space (and there are perhaps thousands of those). I have problems with guides in this case because then it turns into a chore replaced with instructions instead of adventure. So, either chore your way through the game, or spend hours wandering around 37 rooms you’ve seen 18 times already… just to find a key/switch. To reiterate: the moment I use a guide is the moment I lose all interest in the game.

3. When the guide plays an important part of the game. These sorts of guides come packaged with the game; although, this has been very uncommon since the mid-1990s, and it’s generally split into two sub-types:

A. Necessary guides, it wasn’t out of the ordinary for guides to be an essential part of the experience. In the old days, certain types of games (namely the ones I liked, RPGs, adventures, strategies) were less intuitive and didn’t give all the information. They often required a guide for details not shown or explained in the game. Example: in the NES version of Final Fantasy 1, the stats for weapons (who could equip them) and such weren't in the shop menu, but on the back of a big fold-out guide, along with other bits and bobs of information. You didn’t know the value and usage of the weapon until after you bought it, that would later be included in future FF games and fixed in later versions of FF1. Even in the 1990s this stuff still happened, Lord of the Rings on SNES required the maps or you wouldn’t know what to do in the game. I kinda hated these because if you lost them the game became almost unplayable.

B. As a game enhancement tool: Sid Meier’s Civilization 2, where you got all the history and such on the various buildings, countries you could play, and such. But I think the best example of this is the Earthbound Guide. You don’t need it to play the game, but it makes the whole game feel like a vacation, as it treats each new town as a tourist destination. There are ads for in-game businesses, background stories of characters and locations, and all sorts of other details - it was a vacationers pamphlet. You can play Earthbound without the guide, but it’s a better experience with it. So I like these sorts of guides because it adds a whole new dimension of fun. I love these.

In fact, I think the Earthbound Guide is one of the all-time best accessories for an individual game.

This is a great question.

When I was younger -- during the SNES/N64 years -- I had no qualms about using guides. I think I still have my Ocarina of Time player's guide lying around somewhere.

Now, however, I can't bring myself to look. I have this compulsive need to figure out something myself, no matter the mental toll it takes. Looking at a guide does "ruin" the experience for me, a little.

So I played Phoenix Wright: Spirit of Justice last night and was supposed to find an inconsistency during a cross examination. I failed to see it. I searched long and hard, patiently and thoroughly, but I couldn't find it. That annoyed me so much that I looked it up in a guide. The solution didn't make much sense because I was supposed to disbelief in the proof in my bag and argue against a black on white fact in an autopsy report. This is the sixth game in the series and you are taught right from the beginning that you always have to fact check everything against the hard facts in your evidence, so now when suddenly my evidence was supposed to be false, how on earth did the game expect me to find this?

I am too old to suffer through trial and errors and my backlog is way too big to waste my time with crap like this. After all this is said and done, I will still try hard to do everything on my own. It's only when I get really frustrated that I look something up.

I generally avoid using guides on story-focused games. I tend to reserve using them for when I'm going for the platinum. For Souls-like games, I use a guide to get advice on good builds and where to find certain weapons but when it comes to fighting actual bosses in these kinds of games I don't use guides at all.

Yes, I think you can still have fun using a guide; even if it's a story-heavy game.