The platform economics of streaming services incentivizes musicians to release a larger quantity of short, catchier singles that work well in playlists, instead of putting out a sonically diverse album.
At the same time it's never been easier for producers of niche art to find their audience and capitalize on it, simply because the cost of production and distribution is nearing zero and there are basically no more gatekeepers (in the traditional sense).
This. Erosion of quality in any kind of art. It's cheaper to do 3d movies than animate. It's easier to sell simpler ideas than a complicated story with a deeper meaning. You also see this in music with stuff like autotune.