There are compelling alternatives for many of the platforms you mention; what was happening to OF amounted to a complete disqualification from infrastructure.
If you're de-platformed from YouTube, Facebook, etc, you can still publish your content and share it. You have a distribution issue, you don't have an "ability to perform" issue.
If you're locked out of the banking system, your business is done. You lack transactional alternatives.
The number of users is important, and they have monopolies on the user base.
Learn about network effects.