I wouldn’t really say Elden Ring is hard compared to the other souls games because, well…
Spirit Ashes?
In fact, modern Fromsoft games have lower skill floors (than expected) but have very high skill ceilings, like Sekiro wasn’t that hard (for me) because blocking is perfectly fine for most bosses and parrying isn’t super incentivized (except for the charm). Also DS3’s panic rolling. And Armored Core 6’s “wheelchair builds.”
Hollow Knight is also similar, in that just beating the game isn’t too hard, but the post-game stuff is really hard (thus, low skill floor/higher skill ceiling).
Gdash is very weird, as there is no “final boss,” you just play the game, so you could say that the floor (stereo madness) is low and the ceiling (tidal wave) is very high.
All of this to say… I think Lies of P is the hardest game I have seen someone play. The skill floor is very high, and the game expects you to already know the unspoken basics of souls games (being aggressive).