And if they are valuable contributors they will find new opportunities.

Again, paying people based on past contributions is not healthy for anyone. Take sports teams for illustration. It would be like a sports team continuing to pay athletes long after their prime and into older ages regardless of value. This means these athletes no longer find new ventures (coaching, scouting, business avenues) and the team sputters taking the whole organization down.

So in your hypothetical, the best choice is for the CEO to continue paying 10,000 people for doing work that is apparently no longer necessary, basically as charity?

The really annoying part is YouTube gets all their content for free, while every other subscription video service pays for content.