What about banning the actual social media site from the internet?

That also doesn't remove your access to the Internet.

They also weren't banned. Their hosting provider refused to continue hosting them. There are thousands of competing companies out there they can take their business to.

This is like all the grocery stores choosing not to carry brand of product in their grocery stores. You didn't lose access to the grocery store. That brand can start their own grocery store and host their own product if they want to.

Tons of companies host their own infrastructure.

Human rights are not the same thing as corporate rights.