I feel like Sekiro did right what Bloodborne tried to do but sort of failed.
Bloodborne's lack of weapon variety and brown/gray atmosphere really ruined it for me, couldn't really get into it. Played through it once and never again, while I replayed all the souls games multiple times - even fucking DS2.
So Sekiro goes for the no weapon variety and barely any variety in environments, but does it right by making the bosses extra challenging, making combat more engaging, more unforgiving, and making the areas prettier.
For me, it goes
1. DS 1 for being THE souls game. Strangely, the rest of the games improve upon a lot of mechanics, are prettier, and control better, but still they don't feel like DS1 did.
2. DS 3 tied with Sekiro. I feel DS3's main strength was variety - weapon, armor, quest lines, areas. The amazing DLC and kino ending make it hard to top. Sekiro meanwhile is something new and interesting, though it has its faults - like the huge fucking disparity in difficulty (bosses really challenging dmg sponges, mobs piss easy). Still a great game.
3. Bloodborne - unique, fun, but lacks variety massively and is not as memorable the above.
4. DS 2, just a massive disappointment mostly. Did a few things right, but not enough.