Mastodon seems like it could work relatively well.
The other side of the issue though is for social media to feel “social” now, people, consciously or not, want to feel connected to brands and advertising and popular culture. Social media, now more than television or magazines used to, generates our water-cooler moments. It generates the content we sit right here and discuss - it generates memes. These fringe alternatives aren’t popular because the they lack gravity. Gravity comes from investment. Investment comes from potential; typically, potential to make money.
But yeah, group ware, et al, could work for smaller groups. The friction there is getting people to install, and give a crap about, another app on their phone.
Reddit has been generic for several years now. It’s, mostly, addictive trash content. I miss individual subs but the algorithm for popular / front page posts is doing the same thing every other social platform is doing. If that’s your jam, go for it. I value my time enough that I don’t need to be entertained by an algorithm. I hate it. A lot.
Edit:
I mean, I just went to reddit.com and the top post is a 21 year old married woman asking how to tell their 18 year old cousin they stink because they only shower every 3-4 days. THIS is engaging content? WTF is wrong with you people? This is why I’m thrilled to have left that dumbass platform.