There is a massive difference between having to learn something and having to "trial and error" your way through an encounter.
There is no difference because it's always trial and error. Every single game in existence is like that. That's what "learning" is in a video game. Always has been.
Mario was trial and error. Nioh was trial and error. Doom was trial and error back in the day. Even Bioshock which i just finished, a game with fairly simplistic design and gameplay, was trial and error.
It's how game design works at a fundmanetal level. The only way to know if you can make that jump in a platformer is to try it. If you fail, you need to try it again until you get a grasp of the timing and distancing.
The only thing that is different about Elden Ring is that it's more difficult. That's literally the only distinction. And the fact there's more to understand about the game, whether it involves more trial and error or not, means there's more to "learn".
Technically both are classifiable as "learning" but are hardly the same. Falling once into a lava pool to learn its instadeath and having to die 10 times to a boss to learn his whirlwind attack is undodgeable are two very different processes and experiences. Even if the resulting end knowledge is technically the same.
In video games, there are things that you can learn on paper (I.E., the fact a boss is "weak" to a particular damage type), and things you can only learn through experience. Action games, for the most part, focus on the latter. It's still learning in either case though.
No, you cannot. Reaction windows and level design are two fundamentally different areas of game design and do not operate on the same level nor do they test the same skill/capability.
It's the same in terms of the discussion we are having.
In Thief, understanding a level involves a great deal of backtracking and retracing your steps. For every path you take there are alternative routes and there's no way to know where they end up until you follow them. And in order to make sense of the whole level you often have to go back and follow the same paths several times until you commit them to memory.
The process is the same, even if the underlying nature of what it is that you are learning is different, because learning is learning, doesn't matter if it's a spatial pattern or the timing for a dodge.
A boss whose moveset has reaction windows that are consistently brushing against the limitations of input lag is a test of patience, not of learning or understanding capability.
Dark Souls was always a test of patience. It was considered one of its chief virtues when i got into the series back then. There's still learning involved though.
You simply have to know the exact animation tell and mash the button with borderline frame perfect accuracy otherwise you are done.
Yeah, you simply have to
learn the animation tell and the timing.
This means that any boss designed in this way inevitably comes with a "mandated minimum failure rate" before the player can realistically respond to what is even happening on screen.
I have no issues with that whatsoever. That's where my analogy with complex music comes in, because in that too there's a mandate minimum failure rate before the listener can realistically claim to be able to understand what is going on in the music.
Other genres, like schmups, also have a mandated failure rate, which is actually far more massive than anything in Souls. Show me the person who was able to get through the final stage in DoDonPachi first try. There are games, like Battle Garegga, which even play on the fact failure is INEVITABLE no matter your skill level. The game keeps getting harder the better you play and then the strategy is to know WHEN to fail.
And Elden Ring is not even remotely as punishing as those kind of games. You have things that can edge your bets and cut down failure. You have healing that allow you to recover from mistakes. You have tools that you can use to shorten the duration of the fight, or stop the boss in its tracks (like in my fight with Messmer where i basically stunlock him throughout his entire second phase by abusing the stance mechanic). You can use stuff like bleed or rot to cut down on the boss, you have tools like parry that can cancel entire combos.
There's tons of stuff you can do in the game to reduce the difficulty and downplay the frustration. The ONLY time what you are complaining comes into play is if you are trying to do a no-hit run on the boss, possibly while limiting your damage output, and 99% of people don't do that kind of stuff.
No player will catch the tells in the same amount of time and some may simply never.
So?
Your last point about input lag is both irrelevant (you can make the same argument when it comes to other games) and false (FromSoft games are designed for console hardware, which is fairly standardized).