Queen's Gambit only got funded because the Netflix folks saw the boom happening in chess streaming before it. Pogchamps was probably the biggest single factor if you want to go looking for that. It's almost certainly why Netflix wrote the check. For anyone unfamiliar, Pogchamps is a tournament organized by chess.com that paired famous streamers with chess pros as coaches. It's genuinely some pretty fantastic content.
There's also pretty substantial evidence the later parts of the boom were fed by COVID.
Chess streaming had gained critical mass before that, and as the sibling comment points out, there were a lot of conversations happening in relation to how chess was clearly gaining momentum, particularly on twitch, before the first actual pogchamps. I was more using Pogchamps as a placeholder term for referring to the overall boom of chess on twitch. That is definitely why Netflix funded it. I've been told this somewhat directly but can't elaborate further than that.
And I say that as someone who was watching Hiarku on twitch in 2018 and even wrote long post on this site about why Chess is the fastest growing esport" in 2019. [ I seem to have lost which account I posted that under however, I maintain separate work accounts and suspect I posted that one one company time (oops!) ]
But looking back, I was over-optimistic, not about Chess' prospects as an esport, but about how much it had really grown given what happened when we saw a real boom from the pandemic, from xQc and pogchamps, and from the Queen's Gambit.
There's also pretty substantial evidence the later parts of the boom were fed by COVID.