This may be old news to some, but maybe it will help a wayward soul somewhere....
Vivaldi was really slow when starting up, and it would stay slow with multiple cores pegged at 100% on my Linux system. Eventually it would crash and I'd have to start it back up again.
Slow in this case means delays in responses to clicks, scrolls, etc.
Anyhow, I discovered that scanning pages for RSS feeds was enabled. I disabled that and my browser starts up very quickly now.
If you have a lot of tabs and RSS scanning is enabled I believe it tries to load every page and scan the contents, but it was too much for my fairly beefy system.
tl;dr: disable scanning for RSS feeds if you don't use it.
It wasn't always followed on Reddit, but downvoting there was supposed to be for comments that don't contribute to the conversation.
Here the guidance is looser -- the docs don't address comments, but do say to "upvote posts that you like."
I've tried contributing to some conversations and sometimes present a different viewpoint in the interest of thought exchange, but this often results in massive downvotes because people disagree. I'm not going to waste my energy contributing to a community that ends up burying my posts because we have different opinions.
That's true on Reddit to, so I'm kind of being tangential to the original question. I guess what I'm saying is that some people might feel like I do and won't engage in any community, be it Reddit or Lemmy, if it's just going to be an echo chamber.