When you ban a player for whatever reason, only their steam user ID gets banned. It's a simple matter of creating a new steam account and share ME via steam's family share to the new account to get access to a server again. This works vice versa, like if secondary (family shared) account gets banned, but the main account is not.

I would like to request an opt-in to also include linked accounts like this to prevent exploiting users to join servers where they are already banned from.
in the past, this was a huge pain in the butt when grievers constantly made new accounts and caused carnage on a server world.