Continuing my post here due to the character limit:
What can we do?
Votes
I think we all know votes are broken. They just show the agreement level of the mob. Not necessarily connected with quality or if something is interesting to read. I think ultimately that's unfixable. But I'd like to invite you all to vote more. People who write posts or comments need to see it's worth typing it. There has to be some interaction or we're just wearing out people who contribute. And remember to vote on comments, too. Be generous.
Posting the news
I'd say don't do it too much since we already have RSS readers and news sites. But I'm willing to yield with my personal opinion. But(!) Please only post articles that you've read yourself. If it's too boring for you to read, it's probably also too boring for the other people to read any you're just contributing to make this place be littered with random noise.
Posting links with no attached (body) text
Connected to my previous point: Ask yourself: "Why am I posting this?" Is it because you want to discuss something? If yes: Put in a minimum of effort and contribute something yourself. At least write one or two sentences in your post and don't just dump a single link. IMO you should also write a short summary for your audience so they know if they want to click on the link. If you respect them and their time.
Reacting emotionally
We all do that. Just take a step back every now and then and see if your reactions are balanced in a way that you're comfortable with. Remember you can always down-vote someone and be done with it and not start an argument. But you don't need to keep silent. Especially if you're reading a text like this and making an effort, you're probably on the good side, so I don't want you to surrender this place to the people with less approvable behavior.
Be nice
I'd say everyone of us shapes this place by their behavior. If you want it to become a nice place, be nice yourself. We all know that's easier said than done, but we can make an effort.
Diversity
I think diversity is baked in to the Fediverse. We can have different instances with different focus, different moderation policies and a different tone of conversation. The technology isn't there yet to give everyone what they want, but I think we should embrace our diversity. And do something constructive with it. That's not easy. Some people like to have "free speech" and no moderation. Some like to have civil discussions without trolls and people who are constantly wrong, yet very aggressive and argumentative. Some are meme-lords or whatever and everyone is here for their individual reasons. I don't think we need to completely unite or agree on things. But we have to find a way to get along... Be liberal with other people who might be using this place differently. But don't tolerate unacceptable behavior.
Moderators and developers
You have quite some impact here. Use it wisely. Be fair, open-minded and make this a nice place for us.
Netiquette
People figured out in the 1990s, communicating over the internet is slightly different from communicating in the offline world. They wrote an unofficial code of policies that encourage good behavior on the Internet. Used to regulate respect and polite behavior online. It's called the Netiquette (If anyone has a better link, feel free to provide it to me.) It's a bit outdated so let me copy some guidelines and paraphrase:
Never forget that there's a human being on the other side!
Read and think before posting
Share something new
Your posts represent you - Be proud of them
Consider your audience
Be careful with humor, irony, and sarcasm!
Be conservative in what you send and liberal in what you receive.
Take your time when writing a post
Make things easy for the recipient.
Don't waste people's time. You should put in a bit more effort and in return save hundreds of people from spending extra time.
People's culture, language, and humor may have different points of reference from your own
Avoid posting "Me Too" messages, (use an up-vote instead)
Consider using Reference sources (Documentation, Newspapers, Google, ...) before posting a question.
Use spoilers when applicable
Don't get involved in flame wars. Neither post nor respond to incendiary material.
Don't feed trolls!
Deal with the issue, don't attack the person
Utilize the moderators. Flag/Report unacceptable content