I think it is for emphasis and for clarity. It is to clarify that the ban isn't temporary. A ban could be revoked or it could have a time limit. Permanent means

I think it is for emphasis and for clarity. It is to clarify that the ban isn't temporary. A ban could be revoked or it could have a time limit. Permanent means it can't be reverted. I wonder if 'suspended' might also link to the wording within their ToS, so that's why they use ban vs suspended.