this is a thought i've had for a while, but i saw someone today say "why are all the best stories nowadays from small creators?" and i feel like that's become a recent growing sentiment.
the answer is that indie works have always been good (art, music, games, etc.), but one of the big differences between indie and AAA is that you don't hear about indie works unless they're good. if an AAA project is bad, it usually becomes the outrage of the week, because the expectations are high and everybody has heard about it beforehand. if an indie project is bad, then it usually dies quietly.
there have been some outrages, but it's usually 1) due to very good marketing that causes high hopes (RIP Mighty No. 9), or 2) due to a project that was very good but something happened to it (RIP Them's Fightin' Herds). usually, you don't hear about bad indie projects. usually, you don't even hear about good indie projects. you only hear about the exceptional ones.
with that in mind, the other reasons are a bit more obvious. cheaper tools and programs like Blender are becoming more common, accessible, and powerful, which make it much easier for indie creators to enter the industry and create quality content. at the same time, AAA studios are pressured to play for profit, which rewards cheaper budgets and shorter production cycles.
since a lot of AAA studios are getting comfy with being mediocre, a lot of people are paying attention to indie studios now, and i think that's great! i also hope that it drives AAA studios to higher standards, which cough can probably be achieved by paying their workers and treating them better...