Sekiro has such a clear vision and style and is trying new things for From Software in a couple of different vectors. This game plays much differently than Dark Souls and the world building and storytelling are also much removed from From's typical approach. I enjoyed my time with it, but it doesn't work for me quite as well overall.

Sekiro is about parrying in a way that no other souls game is. You will have to rewire your Souls habits to succeed here, but a couple of smart decisions make the onramp manageable. Parry windows are extremely generous and failing usually just means you block (which has other negatives). It is a super interesting combat system that I had a good time learning, despite some of the cracks showing by midgame.
Enemies have poise that you parry, deflect, and clash your way through, whereupon you can score an execution, killing them immediately. Bosses take 2 or 3, usually marking specific delineations for their phases. This is a cool reward moment that makes these fights feel like balletic swords duels when it works, clashing back and forth as you learn their attacks and exploit them. Fights like Jinsuke Saze and O'Rin of the Water feel incredible as you learn their attacks and execute them perfectly. Your first attempt will be 5 minutes of healing, defending, and looking for opportunities while your winning attempt will be 30 seconds of attacks, parries, and executions. I haven't gotten quite this feeling of complete mastery from any other Souls game.
This is unfortunately undercut in many fights by the fact that poise regenerates very quickly when an enemy is at full health, so you will spend much of the battle trying to deal vitality damage to them so that you can finally parry them into an execution. It becomes a tedious and rote exploitation of their positioning and movement that simply doesn't work.
Some unclear UX around perilous attacks makes things a bit more frustrating and fiddly than it probably should be which is exacerbated by the camera and lockon system not playing that nicely with multiple enemies (each of which is doing a perilous attack on you, good luck!).
The lack of any particular ability to customize your build gives the game a very intentional feel, but also made me feel locked into playing a particular way that could sometimes be more frustrating than fun.
The negatives weren't quite enough to ruin the game for me. I did cheat my way through the final boss and don't feel bad about it.

Narrative in Sekiro is trying to be more linear and straightforward than other From games and they don't quite deliver. There is a coherent throughline, but a lot of what happens and why is either unclear or based in some lore or actual Japanese history I don't understand. There are side areas, but the progression here feels very linear, with basically one way to go to proceed and a lot of story-based area gating. It is fine for what it is, but trades From's strength (narrative through world-building and inference) for their weakness (narrative through direct linear plotting).

I love the style and look of this game. It has muted visuals punctuated by bold colors and environments that are grounded but extremely surreal. Enemies are all based in Japanese history and myth which gives things an authentic and compelling edge while allowing giant serpents, apes, and monkeys firing rifles to exist believably along with spear wielding samurai and agents of the unexplained "Interior Ministry."
Along with Bloodborne, this probably has the most striking and impressive look of any From game.

I like Sekiro quite a bit, but some of the uneven difficulty, combat system weirdness, and narrative stumbles do mar the experience for me. It is worth playing to see how different this sort of combat can be, but don't feel bad about cheating if things get a bit too frustrating.