[p-e-w]

> If you're banned from a popular instance you're not banned from the platform as a whole.

The most popular instances are the platform. Yes, you can run your own instance, with only yourself as a user. Unless others choose to federate with you, that's the equivalent of calling your blog a social network. And if the biggest instances impose their own rules on others under threat of severing federation, the freedom to run your instance as you wish exists only in theory.