I hate when people call Warhammer background "lore"
It makes it sound like it's more than just a setting for creating your own stories and armies through playing games and doing conversions and painting. People treat it like it's real history, unable to be changed in any way and some objective truth when it's not. And "lore YouTubers" definitely don't help, since they're the ones pretty much directly telling people that it's a fixed story.