How exactly are “communities offering services” a different thing than “hosted software”?
It’s a lot easier to ask Matt down the street to customize or add a feature than it is to ask Google, FB, etc.
Case in point: I’ve run my own email server since 2013 or so. I’ve got friends and family that use it. One of my friends asked if there was any way to setup rules to filter emails and such. I was like “yep” and added on Sieve to Dovecot and setup the webmail (Roundcube at the time) with the Sieve plugin.
Granted, that’s a pretty basic feature that pretty much all commercial email providers offer, but the point is someone asked for it and I made it happen for them.
That’s okay, too.
For me, I only let people I know use them (friends and family) with the exception of my Lemmy instance, of course (and even that’s not wide open to the world).
I’d be running these for myself whether anyone else used them or not. Unless I’m hosting for hundreds of people, the cost to run these services is the same as it is just for myself. Granted, I don’t have people gaming the system trying to backup their entire PCs to their email inbox or Nextcloud, but that’s where the trust factor (and storage quotas) comes in.
As far as being responsible for all that goes, again, the small audience of people I know personally lets me explain that it’s all “best effort”. That said, I do take my own backups and high availability seriously and they benefit from that.