Because there were external forces that helped propel and keep YT aloft. If smartphones and so on had not come into existence, it would have crashed and burned.

"Uber is similar - they shouldn't exist, they basically broke the law in most countries they moved into, brazenly violated all kinds of barriers that kept taxi industry completely entrenched for decades"

And here's a simple way to demonstrate my point - backed by VC - Uber accelerated its growth and got to the point it was so widely adopted nobody could stop them from operating.