Why Does Reddit Fuzzed Votes?

The rules in question were created to prevent spammers or vote manipulators from seeing exactly how their efforts were affecting a given post — they changed the number based on hidden variables defined by Reddit, “fuzzing” the upvotes and downvotes.

Why are Reddit Upvotes unstable?

Reddit doesn't display 100% accurate vote counts. It applies a fuzzing process to the numbers so that you don't know the actual numbers. This is done so that people attempting vote manipulation by bots and stuff don't know if their votes are actually being counted or not.

What do votes do on Reddit?

Vote. If you think something contributes to conversation, upvote it. If you think it does not contribute to the subreddit it is posted in or is off-topic in a particular community, downvote it.