You didn't really say much of what does it do wrong or right, you seem to just try to convey a for-granted idea.
I've been an msft employee for a couple of years and teams... Was ok. I prefer slack, but meetings, video, messaging, formatting, etc. was just fine in teams.
What kills this platform is entities other than people participating. I ignore anything else of facebook baits for posting/visiting.
In the beginning I added artists and maybe some companies I fancied: that's a huge mistake. FB is only an ad framework for these entities and they are going to occupy 100% of your feed.
You erase all that and I started to see some friends doing stuff again, which is nice. I still think tho
the algorithm to generate your feed is real s*.
I set up immich backed by ceph last week and I got everything migrated via immich-go, with all metadata albums and all.
Had to change some parallelization option, but otherwise it was a breeze.