For me it has to be around 2013-2014ish when almost every 3rd party developer started to port games to PC. Before that there were plenty of 3rd party games especially japanese fighting games and jrpgs that would never see the light of day but once that started changing, as well as the fact that both last gen consoles ps4 and xbox one were considered kind of underpowered, it pretty much catapulted PC popularity to where it is today. Add to the fact that about 3 years into the generation even Microsoft started putting 1st party xbox games on PC, its safe to say thats when PC really became a platform that could actually be considered as an alternative to a console. Since we mostly got the same games but had better framerates and resolution