All major platforms have mechanisms to identify ban evasion. It's not so easy to create another account when, for example, they ask for a phone number.

In the U.S. at least, it is trivial to buy a new SIM anonymously. But really, you should refuse to use any platform that requires a phone number in the first place. These companies make it implicitly very clear that they want to control you and extract every bit of information that they can from you.

Slightly unrelated but GH's ToS clearly only permit one free account per person and I've heard they sometimes enforce this