mustardoverlordI think some of the examples in this thread are definitely reductive in focusing on a single person rather than a more general trend
metagame evolution is general is interesting because the idea of using a certain weapon for instance is nothing new and in any troll game/unserious half of tf2 youll see people use direct hit, force a nature, quickies, etc. but eventually something like that actually gets seriously considered for its merits, usually by someone who just has fun playing with it, and their success or playstyle or whatever gets noticed by actual competitors who then use it for no reason other than getting a competitive advantage
not only is it a more communal shift but its hard to pin down whats just some guy trolling and whats the actual seed of a serious metagame reconsideration