piracy probably wasn't the reason they won back then, but I think the point was that the change in IP enforcement since then might be the reason they can maintain their lead now

They had a rough start until googie acquired them. Lot of traffic, little revenue. It was the infusion of billions of dollars at the time and in the landscape it existed in that made youtube successful.

You would need a few times that to make it work all over again. Either that or some sort of decentralized framework with decades of volunteer man hours and hundreds of millions of dollars of volunteer hardware and network power to displace/replace it.