How is XIII and XVI trying to be open world? If anything, a common criticism is their games became too linear after IX, with a lack of a overworld.

Even XV was criticized because the second half of the game is too linear, even if the first half is open world 

Meaning the world and travel time is just too big and time consuming.  I miss the days of dungeons., short and sweet.  Focused.  I don't want to walk 2 hours from point A to point B.

Do you know what series identity even means to be posting this? It's not just about same characters, world etc it's also about the central aspects and philosophy defining the series. FF's defining identity was that it was always a really good story with lite but adequate gameplay to compliment it, that's how the series started and was up until FFX the gameplay was similar but the underlying system driving it whether material, job system or junctioning etc... would change meaning different thought process and approach was required with each. It was like a heavily interactive story. 

Changing identity each game isn't as good a thing as you think the is a reason why no such franchise really exists and why FF has displayed no growth because of it as the is no way to build up or retain a fanbase with it this is why these debates are even a thing about FF as other series have changed while retaining an identity.

Every game can be a new game without dropping identity and what's ironic is FF has not done anything innovative per say it's just borrowed from other games in FFXVI's case DMC and not done anything new Nier and Tales series for one has been doing action combat for over decades. All well and good saying for better or worse problem now is for worse in today's era is punishing.

It's better to just create new IPs for new identities that way you grow your library and allow current IPs to continue on with their own identity. 

This is only an issue (if anything) in the first half of XV and XII, but XII has dungeons so I don't know exactly what you're complaning about. There is no difference in map design between X, XIII or XVI, except by the random encounters which were removed on XII

In any case, in all 3 you need to traverse a constrained and direct map where you fight minions and level up until you reach the bosses. If you want to remove it, then you only have the bosses and the cutscenes

As I said, a common (and valid) criticism about the series starting from X is that it became way too linear

Well your opinion is your opinion.  Mine is mine.  To me the series has lost focus.  Too much walking.  Too much not knowing why I'm doing something.  Too long to get from point A to point B.  The new FF games seem to have large scale for the sake of having large scale.  Scale only has impact when it is designed with intent.

I loved the series on the SNES, ps1 and ps2...  don't care about it anymore.

To each their own.

To this I highlight Shinji Mikami's interview years ago about God Hand, he highlights that developers can at times be given too much freedom in achieving their vision and the result can be worse than if they weren't given freedom. The basic message is art is always just that and only appeal to those who gel with it which is what happened with God Hand while games may utilise art they're not in themselves art. 

I'm totally okay with people not liking the gameplay, people who hate the linear aspect as well as the walking (which is basically the gameplay loop of 90% of FF games) is completely fine 

But the games are not trying to be open world, that's the opposite of what's happening

Well, the games keep selling a lot, even if not as much as other IPs and they have a huge following, enough to keep vesting AAA budget

While they might be concerned with sales I don't think they have reached a point they should step back form doing what they want just yet, their games sell well enough and are still very liked 

I don't think Square have ever issued a mainline FF game (sequels and spin offs are different) that scored bellow 80s. Even XV who suffered devopment hell and is arguably one of the most hated entries still sold 10 million

While FF seems to receive much stronger criticism than other IPs I believe this is just because people have their own expectations of what an FF game should be or look but keep coming back to the franchise, while in other franchises if you don't like an entry you don't have many reasons to comeback, as the sequel is likely to be similar. 

The are factors you're not accounting for here for one with every gen costs increase especially for bigger games as development is longer and releases are fewer secondly I highlighted already earlier in the thread why XV sold better it was multiplatform plus I'll also add that it was also the first new installment in a decade.

FF receives criticism because it's been an inconsistent franchise for over a decade now, again having an identity is not and was never a bad thing it actually helps developers as they know who their target audience are beforehand as well as things to build up the userbase and it helps reign in freedom to avoid what Mikami pointed out and this leads to developers refining a series.

Here's what's happening with FF we've had a linear disappointment in the XIII games to a MMO that required two attempts to get off the ground to a very bland open world game to now a DMC lite title. It feels like a roulette of trends it would be better if some of these were new IPs. 

I'll restate.  Too big is my problem.  FF doesn't need to be 80 hours.  To be fair it isn't just a FF problem, but with many games.  Bigger isn't better when it is unfocused, fluff and tedium.