Your perception of lemmy has been tainted by the kind of communities you interact with. You and I have wildly different experiences on this app.
Part of the reason you feel this way may be caused by you being subscribed to unpopularopinion, an inherently contrarian community. If you'd like to be happy, stop following that community.
I also encourage you to avoid engaging in political conversations with non-rational people: It is extremely unlikely that they will change their minds, and even if you do reach an understanding, that conversation is really likely to leave you with a sour feeling.
In comparison, the communities I'm in are mostly about memes, IT, privacy and LGBT stuff. No news about the war, and no political arguments with random, possibly deranged, users.
The instance I'm in doesn't even have downvotes! Depending on how you use lemmy, you can have either really good or really bad experiences. I recommend u to try to avoid conflict, and maybe even switch to a downvote-less instance.