§230 says that YouTube is not liable for any content that users post to its site, regardless of how much moderation of that content YouTube does or doesn't do.

Everything after the comma in that sentence is actually the entire point of why §230 was passed; prior case law held that YouTube would be liable for all content if it did the barest amount of moderation.

Is restricting content and banning content not a form of moderation?

Restricting or banning content would count as moderation as far as §230 is concerned.

It has nothing to do with section 230. The idea that section 230 prescribes different treatment of publishers is an oddly persistent myth.

It's persistent because RW media keeps pushing it as gospel.