It's popular here because people don't feel able to express themselves to others outside of such an online platform. That and prostitution
Elon wants to export this dystopia to the rest of the world... I joke, I doubt he has any clue about anything beyond the user counts.
This is true for all companies though. It's arguably happening to Google now, and to Facebook, and, hard as it is to imagine, will happen to Apple some day, even if that day is decades away. GE was an icon of corporate competence in the 80s and is now in parts. Toyota has long seemed invincible but now has to make it through the transition to electric vehicles. Intel, Microsoft, etc.
The hard part is not predicting that a corporation will decline, it's getting the timing right. (Just ask Michael Dell, who in the mid 1990s famously said he'd shut down Apple and sell it for parts if he was in charge. Red Herring magazine kept predicting Amazon's imminent collapse and at least half the people reading this don't even know who that is because they very much died first.)
I know people love to crib Hemingway's turn of phrase, but I don't think it makes sense here. Because it's the opposite, right? Sudden first, and then gradual. There's some big catalyst, and what remains afterwards slowly dissipates seemingly interminably towards zero. Even in notable cases like MySpace, which still exists, it's just "gradual" at first and then it's still "gradual" later, too.
From an information perspective, that makes tracking it over time more relevant, not less. But of course also means it's a lot more work.