Before evolving concepts, both Blackpink and Twice had relatively easy dances. But Twice was the only one that got extreme backlash for it. Personally, I think it's because of some kpop fan's misplaced hatred of cute concepts and how they think cute = easy. But I want to see what other people think.
(also what happened with Jennie in 2018 doesn't count. She got backlash for being "lazy", not for the group's dances.)