Whilst it's DRM free, it's still licensed copyrighted content that cannot be shared unless the license permits. BandCamp's terms of use state that they take non-exclusive rights to sell and distribute works on your behalf, but they do not grant those same rates to buyers.
DRM is not Licensing, but a mechanism to enforce a license.
I think OP is implying that the sharing provided in funkwhale is likely violating the typical license terms of any purchased music, therefore is preventing a musician from making money from streaming services which have appropriately licensed the music for streaming.
Buying a license doesn't mean that you own the work, just that you have the right to play it in specific circumstances (most of which nobody pays attention to anyway). I'm sure we've all played a song on a loud speaker for others to hear, but again that's against typical license terms.
So you are aware people sell things they make, to live? and they hope not to sell to just one person who's paying $1 to put it online for 100,000 people to have it not sold.
And that's ok with you because you don't, or don't need to, make a living creating music.
Try thinking about this from the perspective of whatever it is you do to make a living.
