As far as I know, YouTube always assumes one account is used by one person. Since I use it mostly on the television, this isn't true. It stays logged into my wife's account, but we both use it. So it's constantly fighting between me going in and watching sports highlights versus her going in and watching ASMR hands in slime face massage simulation videos. The recommendations are schizophrenic and all over the place. Other streaming apps that were meant for television first allow you to assign multiple user profiles to a single account.