I think something that plays into this for products is that there is a lot of obvious incentive to making the function of things more efficient to build first. But as we become more efficient at building just the function of things, adding diverging flavor takes up a higher proportion of cost even if the cost of it itself absolutely stayed the same.

I do think broadly we're probably oversaturated with the flavor of high definition and 'realness' in the mainstream. But I don't think this is the end of taste evolution. Recently I've been looking back on movie posters from past decades. I think movie posters and advertisements are decent to examine here as they play to the mass taste of their time. In isolation of their moment and market there was a uniformity in style, yet over time it still progresses despite keeping it's core features.

Globalism is perhaps disappointing here because it means we have few equally sized parallel 'mainstreams' taking place. But at least with the internet, you can still just as rapidly find many actively diverging styles that are otherwise relatively niche to the mainstream.[1]

1. https://aesthetics.fandom.com/wiki/Category:2020s