Why is there an option of upvote downvote in Meta SE? It never affects my reputation.It neither increases not decreases reputation. Then why is it there?
The purpose of votes isn't reputation. The purpose of votes is to determine what the community thinks of a particular post. It happens that on main, posts that are voted on are rewarded/sanctioned by reputation, but this isn't the case on meta. It doesn't mean votes are pointless, because they still fulfill their primary purpose: determining what the community thinks of a post.