Similarly to On the importance of descriptive and informative titles for posts, in this post, I will motivate the importance of regularly voting (both upvoting and downvoting).
Since I've been elected (by you) a moderator of this community (about 1 month ago), I've noticed that only a few people regularly vote (either up- or down-vote). For example, only 8 people have apparently cast an upvote or downvote during this month (and half of them are the usual suspects). You can see the statistics here.
Now, if you look at these other statistics of our site, you will see that we currently have more than 3k visits per day, 467 avid users and 30,504 total users. We also have more than 10 questions per day.
Our statistics are generally looking good (and I think they have been improving), but not all of them. For example, only 67% of the questions are answered. Why? This can be due to different reasons. For example, maybe our community needs to be even bigger or maybe most of the visitors are only interested in reading, rather than asking or answering questions. However, I think that one important reason why these statistics are still not perfect can be due to the fact that especially regular and avid users are not voting enough.
I acknowledge that not all questions are interesting (to everyone) or relevant and that certain answers are also not awesome, but I think that votes shouldn't just be cast in those cases, but also to assess the correctness of an answer or the clarity or general quality of a question.
Everyone has its own reasons to be on a Stack Exchange site (in particular, AI SE). One of those reasons is probably to learn more (either by asking or trying to answer a question) and the other is that you feel empowered (in my opinion) by your peers when you receive an upvote and, when you receive a downvote, hopefully, it's an indication that you need to improve (although, often, this can also mean that someone simply doesn't agree with you, etc., etc., but I don't want to dwell on these corner cases). Voting is one of our fuels that allows us to prosper and grow. If we don't regularly do that, the community can stagnate and we don't encourage especially new users to keep visiting our site.
Now, do not go around and start randomly upvoting or downvoting! You should first make sure that the question or answer is good enough for an upvote, according to your knowledge, which implies that you should first read the post. However, if you do not have a good knowledge of the topic, I strongly discourage you to cast a vote, because that vote can be misleading. Maybe this is also one of the reasons many people don't cast votes, but I still think that many people often don't vote only because they are lazy, they forget about the voting system or maybe they vote only when they see excellent answers that show them new insights. Again, no, votes should ALSO be used to assess the quality and correctness of the post, and not just its originality or interestingness. Of course, we expect more original and interesting questions to receive more votes.
Finally, although concluding a post with this may look pessimistic, I want to stress out that you should also downvote when an answer is incorrect or a question is unclear, etc.