I haven't finished it, but I've gotten far enough to know that it is. It's not a mechanically complex or nuanced genre.
What you're saying doesn't make sense. It doesn't just have similarities. It is functionally, mechanically identical to a dating sim because that's what it is. That's like saying "just because you point and shoot at enemies in the first person doesn't mean it's a first person shooter." That's literally the argument you're making. SMT is a monster collecting JRPG where you don't ever have to catch a single demon. Sure, you're making the game needlessly difficult by not playing it the way you're mechanically and narratively incentivized to, but I mean you can grind so it's just an option so I guess it's not a monster collecting JRPG series after all.
Like I said, it's been a choice in every Persona and every dating sim. These mechanics don't exist for no reason, and they don't have an insignificant place in the game. Just because you can choose not to do them doesn't mean that you aren't meant to. The game becoming more difficult because you don't utilize a mechanic means that the game is literally punishing you for playing incorrectly. And like I said - you don't have to ever date anyone in any dating sim, ever. It's always a choice. P5 placing less emphasis on romance than other Personas or even other dating sims doesn't mean that there's no emphasis being placed on it, because there is.
EDIT: And again, I don't mean that as an insult. I literally think Persona 3-5 are the Hunter x Hunters/My Hero Academias of dating sims. It's not a bad thing. But that's what they are. It just feels like people are ashamed to like a dating sim because there's a stigma. A stigma Persona drop-kicks in the ass, so I don't see the big deal.
Well, I see it as a different thing. See the bold? you just describe what Persona is. A dungeon crawling/fusion persona/persona collecting JRPG with dating sim features in it. I mean, majority of your time will be spent in conquering Palaces, Castle, Tartarus with the help of your Persona because that is main aspect of the game. That's your goal not dating with the confidants because If you don't go to the Dungeon then it is game over.
Also, Persona 5 will not punish you if you have the right set of Persona with you so even if you don't interect with some of the confidants you can still easily beat Persona 5. Focus on the skill set and the right persona before you traverse to the palace and you will dominate all of the Shadows in it. For me thats the core mechanics of the game. Capturing and Fusing persona so you can get the skill set that you want. They even have this Treasure monster you can have to provide you more skillset that you can have for your Persona.
That's why I love the upgrade of the Velvet room for P5. I am not even talking about the weakness of the shadow but how you will utilize the strength of the Shadow as well to your advantage.
No worries I am not offended but Persona roots is still in collecting Persona and it's JRPG elements. You go to the dungeon, you gain a persona and fuse it to gain a more powerful persona and you level up. It's like you telling me MOBA and Warcract(strategy game) are RPG because you gained experience and level up and you equip weapons and armor.
But one thing I can agree you on is the dating aspect that was integrated to Persona is one of the welcome addition to the game. It made the game more unique and became a separate series to the Main SMT.
That is literally not even close to being true. Half of your time is spent in the overworld, if not more. It would literally be exausting if you spent most of your time fighting monsters in any RPG, let alone Persona. Most of your playtime is spent managing time. Persona isn't about exploring dungeons, it's about exploring themes.
You're literally forced out of dungeons because of the way resources run out in this game. And I'm not saying P5 isn't defeatable without some confidants, but you do not have freedom of play without them. You yourself said it - the game is more difficult without them. That is a punishment. It's also more limited. You have to play a certain way to win without playing the game the way it's designed to be played, both mechanically and narratively. It's like a nuzlocke run in Pokemon. It's not meant to be played like that. (Also like 1v1/no items/final destination Smash, but I won't get into that)
And again, you're mischaracterizing "dating sim" by putting too much emphasis on the dating aspect. Every time you read a book and gain the intelligence skill and loose time on a limited amount of days and hours, you're playing a dating sim, and to discount the amount of time and mechanical/thematic relevance spent on that is to be extremely disingenuous. Persona, as a narrative franchise, is literally about building bonds and exploring the psychology around that. The mechanics are designed to facilitate that, and half of those mechanics are dating sim mechanics.
EDIT: We're getting off topic though. PM for further inquiries.