

people do not know how to act properly
They do, in communities where rules exist and are enforced. Anonymity may lead some people to feel more emboldened to act out, but when handled properly I believe the vast majority of them will just settle down and either learn how to participate in good faith or find somewhere else to be. The bad behavior patterns we see in some places are, in my opinion, the result of insufficient social norms and enforcement thereof. This is also a situation capitalists will foster, because it drives engagement and inflates content.
Unless we can force people to act with civility - which implies people being fairly conscious of the consequences of their words and actions
So you already understand that this is a problem that only exists in places where bad actors are given license to continue acting out.

That’s a great question. There are some college courses that can help you answer that. The short answer is “because in terms of the flourishing of an entire species, cooperation trumps competition, but it’s a recent evolution and doesn’t come naturally to everyone”. If we are to flourish and advance instead of strangling ourselves in the crib, we need to stop tolerating the kinds of selfish behaviors that prove detrimental to every society that permits them.