When there’s no algorithm, just a list view feed, upvotes don’t really serve any purpose. I think people like doing it though, so I’d make it just something the liker can see - like it adds it to your “liked” list. The poster doesn’t get a notification or any indication of the popularity of their content.
Lack of upvotes (and downvotes) motivates people to post more than usual, cause there's no other way to [dis]agree or feel agreed with. "Don't serve any purpose" this is a claim that will kill your network before you can think how to shape it.
