Bloodborne covers all bases for me
I feel like we have this thread come up at least annually.
It comes down to how we define perfection, and for art, games in this case, I don't think it's about being all things to all people - that's "Tetris" perfect - but how well a work executes on what it sets out to do.
Bloodborne is absolutely on that list for me. I'd consider Dark Souls my favorite game of all time, but you have meet the game halfway too often over a very long campaign. Bloodborne is just pitch perfect throuought.
I think Mario Odyssey is an example of a "perfect Mario game", where is does manage to be all things for all people, but it does make me long for other titles at moments like Sunshine, Galaxy, and 3D World. The feeling will pass by the next moon.
Tl;dr : I think perfection is relative to the title first (perfectly executed idea) ,the player experience second (perfect for me), and "perfect for everyone" is a compromise.