Bandcamp alternatives have existed for a while. Not just server software, but complete stores. The challenge lies in convincing people (buyers and sellers) to start using them.
But if you just need to easily sell your music in digital format (which is what Bandcamp started as), there are options.
There are, but very few of them seem to provide for downloading full albums in nonproprietary lossless formats.
Not to the artists who put their music there.
Looks like I can buy albums there. Check. Can I listen to a full album? It seems like you only get samples.
It also is very sparse and doesn't really give a great band presence. I'm guessing the selections are populated by labels rather than artists?
It doesn't do much at all for recommendations.
Platforms like HDtracks and Qobuz are not a "Bandcamp alternative" when considering the business reasons that artists use Bandcamp.
Bandcamp lets small independent artists upload their own songs without a distributor middleman.
In contrast, HDTracks only gets music from distributors like established record labels. Example discussion when somebody asked about it: https://gearspace.com/board/career-work/1358709-how-do-i-get...
The main pain however is that some labels (usually Sony) stubbornly don't allow lossless downloads...