Why are you being so condescending?
It's one thing to come at a criticism with the idea that there is some fundamental issue with it.
"I don't like it because for me losing progress sucks, and I'd rather it not be there."
Rather than pulling some nonsense out of the back pocket and trying to make it some hard fast game development rule that everyone must adhere to, like they have been.
No, all games DON'T have autosave mechanics. Yes, many developers consciously do not put use it in service of their game systems and gameplay. Yes, many gamers love them. Yes, there are entire genres that avoid it for one reason or another. There are games for example where preparation is key (Persona is part of them, but hardly one of the more punishing ones) and as a result you know before entering a dungeon that you won't be able to save again until you exit.
And that's the point. And it's an awesome mechanic for tons of people!
Persona 5 isn't even a particularly punishing game. And it's already sacrificed a lot over the years in service of making the game more accessible to people who never were even a part of this franchise for years and never cared for it. It doesn't need to go further.