Sorry, but I disagree with this. The vast proliferation of social media sites speaks to the opposite:
Friendster, MySpace, Facebook, YouTube, Snapchat, TikTok, NextDoor, LinkedIn, Instagram, WhatsApp, Pinterest, Reddit, Substack, Messenger, Telegram, Quora, Twitch, Tumblr, Yelp, Periscope, Untappd, Fark, Meetup, Mixed…
Some dead, some very much alive, some general interest, some more specialized in function, but all of them with millions of users.
Then there’s the streaming services. We who hate signing for cable now sign up for 3, 4, 5 streaming services. Inertia was what was to make Netflix’s first-mover advantage unbreakable. Sadly, Disney+ didn’t get the message.
I just don’t see the inertia. It exists among individuals, of course, but the rise and fall of the names above in a mere 15-year period doesn’t reflect this inertia in the SM space.