This is a trait it shares with every action game in existence, except those that are so braindead easy that you don't need to take into account what the enemy is doing.
Despite the memes, Sekiro is not a particularly hard hack 'n' slash
Lutte said it best, the hardest thing in Sekiro is realising that you (the player) are the problem, in the sense that its the player that creates obstacles when he thinks he can defeat enemies by creatively employing the tools and actions at his disposal, when in fact he's just hurting himself as Sekiro was designed to accommodate this
Once you realise the game just wants you to fight exactely in X way agaisnt Y enemy, the challenges become quite manageable
Furthermore, there's nothing that says you have to play this way. You can choose to dodge or run away at any time, which is often correct but never explicitly suggested by the game.
And so can you do this in pretty much every 3D and 2D Figther...
This is a foundational aspect of these games, it's expected for them to have it
You can also use prosthetics to avoid taking damage in various ways (umbrella, mist raven) or deal damage yourself by alternative means, like using shuriken at range, or lighting the enemies on fire or poisoning them. There are also ways of attacking in melee other than r1 spam, in the form of the various weapon arts.
Most prosthetics and combat arts are quite specific in their function, plenty are ultimately inadequate and all of them are limited in use
In their current implemation, they aren't a solution of Sekiro's lack of varied and worthwhile actions
I think there is a difference in how the game plays and how it feels playing like. I think that people who say Sekiro is a rhythm game just want to say the game makes them feel like they are playing a rhythm game.
Sekiro feels like a rhythm game, because there's just not a satisfactory amount of depth to its combat
The playable character doesn't have a varied and consistently engaging toolset - your most basic combat actions are the most powerful ones, the game never meaningfully progress in complexity past what you learn in the tutorial level
It also does everything in its power to punish the player for fighting the enemies outside its overly restrictive and particular design, even if said design is just boring and mindless - it is common, even in bosses, moments were the most correct tactic is for the player to wait for a specific cue so he can perform a specific counter move (the game literally expects the player to react instead of showing initiative, to wait like a puppy waits for a treat)
Going back to the Chess example, Sekiro is a game where the player only has 3 pieces at his disposal and those 3 pieces are pawns and each enemy piece can only be taken out in a few exact ways
And then, when you get to games like Elden Ring, which tried to add a degree of indterminacy to how the bosses move, people ended up bitching the difficulty is bullshit because now bosses can cancel combos and mix up attacks on the fly. So i guess they wanted a rhythm game after all, right?
Quite reductive. People complain manly that the design of bosses isn't suited for the players moveset and the game balance. Depending on playstyles and builds, a lot of boss fights, specially endgame, consist of either the player having to dodge/block long chain of attacks with small openings that feel very unrewarding and unfun (which sucks because they actually managed to made defending fun and rewarding in Sekiro thanks to the posture and deflect system), or stomping the boss without even having to deal with its mechanics.
Also I would say that bosses don't really have that much indeterminancy in ER. At best they may have a couple of combo routes and respond to the player healing or casting a spell, but they are very predictible and repetitive. Games with true cases of indeterminancy would probably be God Hand and Ninja Gaiden 1/2, where in both games you have to learn to hit confirm and use things like quick jabs/slash to see how the enemy react and then decide your next course of action, and defensivelly the bosses are a lot more deep and interesting. In case of God Hand it almost reward being able to guess what the enemy will do due to the counter system of that game.
Add to that the fact alot of the difficulty from the most egregious ER bosses comes mainly from the devs abusing lazy "gotcha" design mechanics that were quite common in those intentionally bullshit quarter-munching arcade bosses, like:
- inflated HP
- excessively long combos, that don't stop even after the player has been hit
- unreasonable amounts of tracking, coupled exagerated hitbox sizes and AoE
- underhanded animation cancelling
- shameless use of input reading
