@Gargron it's not trivial at all! Doing it safely, will take a lot of people hours to actually moderate, and software support for actually doing that moderation... and more!
The reasons for not having them are valid. So are the reasons for having them.
I would strongly suggest seeking guidance from folks like @timnitGebru and others she recommends.
We can make a difference and build software that supports human efforts to do better. We just need to listen, and listen again.