There's always some people walking around dead malls, even if the mall died years ago. Reddit will be around for at least 5-10 more years but it's overall influence will start to decline. It will be slowly at first but I'd bet three years from now reddit will just be seen as a forum site for scammers, bots, incels and alt-right lunatics (more than it is now).
We're not talking about punishing anyone, we just don't want to hear or see their bigotry. They can have their space and we can choose not to interact with them.