This!
The most talented artists don't want to keep making the same music over and over again and they will delve into music of other styles that they either think will be a challenge or that they enjoy more. Yes a lot of artists make more mainstream music that is less psychedelic and more appealing for the masses. But maybe they don't care about psychedelic, not eveything has to be psychedelic for everyone. Maybe they like that style, the energy the simplicity and less pretension that goes with the more "elite" styles of music. People change and I say let them. There will always be new artists to come and take up the mantle. Look at PoF above, still fairly new and 2 fantastic albums under their belt.
Same here but I find psychedelia in more than I used to