This is a really interesting point, and probably mostly true.
I'd add onto it, that even for people who are doing lots of interesting things, that Instagram soon becomes awkward to use for fear of "showing off" and that it's fundamentally set up as more of a broadcast-to-audience system rather than any sort of interact-with-friends system, which makes it worse.
The parasocial influencer thing works, because it's supposed to be a hollow one-direction "watch me have fun doing X", but real friendships aren't a series of watching each other have fun, they're about actually doing things together and/or having deeper conversations about the experiences, and Instagram fundamentally pushes interactions into "Publisher-Subscriber" model rather than the "Peer-to-Peer" relationship of natural human friendship.