mmm...a lot of people would say it's ridiculously easy, but i interpret that to mean the story, which for the most part in pokemon games is usually pretty simple.
things get a bit more complicated when we go into max raids because the difficulty then is measured completely on the competence of the AI, which i think is rather frustratingly against the player more often than not. this sort of frustratingly incompetent AI continues into dynamax adventures, therefore making shiny hunting there more of a pain than it should be. so i guess it's up to the individual whether that counts as difficulty.
gotta say though,,, the IoA expansion is more or less a joke in difficulty for me. not much i really found challenging there. even mustard wasn't too difficult to beat.
i can't comment on CT yet because i've barely played through it sans dynamax adventures stuff. at this point though, i've accepted that on as scale of difficulty, swsh is a solid like... 4 at the best of times. not that i'm upset over it or anything, it is what it is. i don't expect pokemon games to be brutal, and things like totem battles in sm and ultra necrozma battle in usum are more the exception than the actual rule.
i just hope there's more exceptions in the future.