I don't feel this is a spoiler but the final three bosses in this (two are optional) are unenjoyably difficult. This may well be the first of the modern From games that I don't finish. I'll speak in general terms about the combat but if you want to go in dark, stop reading here.
One in particular, DoH, is the absolute pits, going against everything the game has taught you about combat throughout the whole game. It seems like a Dark Souls reference, which I can appreciate of course, but this game isn't set up at all like Dark Souls, it's about breaking posture and deathblows, and so you can only go for chip damage in a three-phase fight which probably takes a good twenty minutes at least, while most of the boss's attacks will one or two shot you and AOE attacks give you no time to heal. It's a very strange endurance test of nothing you've seen so far. It's just dull attrition where any error or deviation from the one strategy results in death.
The other two are doable, fucking hard and require near perfection, but I could see myself getting there but I don't enjoy the bosses nearly as much as the 'regular' game where stealth, traversal, prosthetics and items all seem to be viable and allow you to mix things up in a really fun way. The bosses, however, feel extremely prescriptive - to me, anyway. It's like, I love Ikaruga and I love the idea of refining execution again and again and again but I don't want to do that all the time, you know? That's why I got burned out on it. It gradually erodes the moment to moment pleasure of the game with the pursuit of victory becoming the only reason to play.
Ehh, maybe a bit grandiose but I'm sick to the back bollocks of Sekiro's endgame. I've also somehow (From conditioning, probably) done everything else in the game, aside from the odd NPC quest which is either/or, and so if/when I do finish this, I'll have very little reason to go back to it.