There’s so many variables, it would be essentially impossible to prove a class is 2% “better”. Sure on a sim or a big aggregate of parses you could see that one does ~2% more damage, but damage isn’t the only factor contributing to success. 2% better is generally not enough to go up a key level (maybe 1 key level in 3 of 16 dungeons).
Influencers will still make guides though.