That's what platforms are. They're markets. Its not like making a couch or something.
That's why those other apps are literally worthless.
It doesn't matter if the other apps are super amazing and they walk your dog and suck your dick and make you live forever. Literally does not matter.
The app, itself, does not matter. Which is why Facebook is allowed to be as shit as humanly possible.
What matters is what the app proxies, which is a market. Those other apps will always fail, forever, because they can't compete with facebooks market because they're not even allowed into that market.