Your YouTube example is exactly what gave rise to Nebula.tv—creators banded together to create an alternative that would backstop them against YouTube's dominance.
>>echoan+qr
All the 1000 of your mailing list subscribers? Or maybe 10k.
You start needing alternatives when you're already established and have a following. With this comes large enoug influence and thus the ability / risk to step on some big toes, including Google's.