I've always found stuff about how technological/sociological advances beget changes in music really interesting. David Byrne's book 'How Music Works' covers this exact point about quantisation and much more.

I would argue that there's probably a lot more nuance here when you look at how economics of music have changed in the last 50 years - it's now so much cheaper and easier to produce and listen to music. There are millions of bedroom producers experimenting with production techniques, and the market for music is completely saturated with more good music than anyone could possible listen to. Record labels just can't compete when it comes to making interesting, creative music, however they can still win at marketing. I think the modern charts now are less determined by what resonated well with audiences, but rather what has been calculated to be the most 'marketable' kind of music, and I suppose a metronomic tempo is an easier sell in this regard.

Also worth noting: a perfect tempo makes a song a lot easier to remix, which can often gain the song a lot more exposure than the original edit.