I mean obviously there are a lot of "chicken and egg" issues, and I'm loathe to say "oh no the apps are all 'good enough' " --- but people are staying on XMeta not because those UX's are good. In fact, in many instances, they're crap UX. And the users know it.
Ditto is already a way better app than Instagram... cleaner UI, more responsive, easier to navigate, etc.
They're staying there because of network effects.
_Short version:_
Some people dropped a ton of money and aren't getting timely returns on their investment.
The rest of us are having fun enjoying the network effects we have... here.