That's great! A community should have interesting discussion, not engagement!
Software wise (Lemmy/Kbin/etc), it's definitely not for the faint of heart currently but that will improve in time. For me though the biggest thing is "One platform to rule them all" is not viable. It will have issues, users will suffer, and this isn't some unique thing we've never seen before.
The more quickly we can regain some aspect of "the web" in favor of users, the better. In my book.
I'm venturing into ActivityPub myself, though focused on UX of link Aggs, mostly. One issue i've seen so far with Mastodon/etc, is that AP works decently for cheap stuff, but expensive stuff like Images and Video still have significant cost. I believe with Mastodon it's all hosted from the source location. Ie you run `tinymastoinstance.com` and one of your "Toots" with videos/images goes viral in federated instances, i think pretty much everyone is pulling the image from your instance. Not sure how much they try to federate the heavy stuff.
Hypothetically they can of course.. but i'm just not sure what the AP spec says about that. It's of significant concern to me, though, since i'm wanting to build software for micro-AP instances and hotlinking files on a micro instance will almost assuredly burn the instance down.
Facebook on the otherhand though, seems totally viable. Identity duplication is probably the biggest issue AP has with a more identify focused application like Facebook. Notably as i learned the other day there's nothing in the AP spec for persisting identities across instances. No private key you can reuse on new instances to identify yourself as the same user, etc.
Did you hear about federation?
I feel like we're not getting nearly as many /r/startrek jokes as we should be at this point.