Up/downvotes are not intended as dis/agreement buttons. You are supposed to upvote relevant content and downvote irrelevant content, spam, trolls, hate, and misinformation/propoganda.
Upvoting on the basis of liking something played a large part in reddit’s decline, where every sub was inundated with off-topic shit-posts of r/funny and r/adviceanimals circle-jerking. They were upvoted for a cheap laugh, but should’ve been downvoted for being off-topic.
The best example I had on reddit illustrating the importance of maintaining the integrity of community topics was this:
Do you think it’s okay for r/wtf material of animals to be posted in r/awww or r/EyeBleach? If r/TheOnion posts were posted in r/WorldNews?
Comments on subs like r/TIL and even r/science became nothing but irrelevant jokes and memes, which buried relevant discussion. This voting behavior is why subs like r/nonononoyes lost their purpose and were spammed with shitty r/funny cross-posts.
I strictly upvote on the basis of relevant content. My wife has thought I’m crazy when I show her something we both are entertained by, and then she sees me promptly downvote it. Even if I enjoy something, I will downvote it if it’s an off-topic post.
Conversely, I upvote dissenting opinions I don’t agree with, even if I’m debating someone, if it is promoting topic discussion. When people downvote out of disagreement, it suppresses dissenting opinions and healthy discourse.
Downvoting due to disagreement is what leads to toxic echo-chamers. (Again, there’s a clear difference in downvoting content promoting hate/racism/bigotry.)
Upvoting on the basis of cheap entertainment promotes off-topic and low-quality discussion/posting behavior.