Was easy not to see in maybe in 2008, then in, AFAIR, 2010 Facebook started tightening the screws citing security first (and, well, there have been good reasons not to give full graph access to everyone at all), but then it became obvious that they were twiddling with feeds and what they didn't like at all was inadvertently giving you tools to build your own feed but without the ads.
There was no alternative. The old internet, frankly, requires people to pay. They don't if they can avoid it at all. This is what killed most desktop software before, and it is what's killing most internet software.
Probably because the most common model is a $5-$20/month subscription to some "premium" version of the site/app. Subscription fatigue is a monster of the industry's own making.
People were paying. Even right now, I'm paying for my own internet connection (two different providers, at that. Three when I decide to enable mobile data). What happens was that platforms decided to be free for both production and consumption, and decided to finance themselves by selling our attention. Other platforms kept requesting that one of the parties (creators or consumers) pay, and it's working fine for them.
What's killing software is enshitification and growing your expenses past your revenues. People are paying for a lot of stuff and understand that products are not free to build.
