I really don’t like the way that Dwight treated Michael in the later seasons

Sure, you could make the argument that he was learning not to be a kiss ass to Michael anymore. That’s totally fine and good character growth. But Dwight wasn’t just a kiss ass in the earlier seasons. It was shown that he also genuinely liked Michael and thought of him as a friend. But in the later seasons, he suddenly despised Michael’s mere existence and wanted absolutely NOTHING to do with him just out of nowhere and it’s never explained where this sudden change of character came from. It gets to a point where Michael even calls him out on this in “New Leads”.