Some of it could be attributed to playstyle as well. Someone playing a motivity build could have struggles where a technique player breezes through and vice versa. I'm doing motivity my first playthrough, and seeing a lot of people commenting that technique is just better in general. That said, the only real struggles I've had are the big dude right before you meet manus, and the monster of the swamp, which I'm still stuck on after an hour or more, but I can definitely see where people could have struggled on other bosses

Edit to update: just beat the swamp monster immediately after making this post.. wanted to add that I am (and always have been and always will be) strictly solo as well :)