I think this is the main disconnect for people.
What a lot of technical people want is a forum. They want to have every problem discussed one time and then if someone brings it up again they can link to it and not have to discuss it again. This exists, it’s called stackoverflow and if technical people want someone to close their question as “already answered” or “off topic” they can go there.
Most discord communities though aren’t attempting to build a permanent corpus of knowledge carefully curated and searchable. Instead it’s basically the polar opposite, someone can show up and ask the question that every beginner stubs their toe on and people answer it and chat with them and help them learn.
It is more work for the people giving out the help, but it is seems like it’s what new users want. A place they can ask a question and get an answer or get someone to ask them questions to improve their question.
A lot of technical people get blinded by their own knowledge. Indexable searchable information is great if you know what to search for, but new people seldom do and they don’t even know the right way to formulate the questions. Asking other human beings that know what they are doing is a good way to learn stuff. Discord facilitates that, people like that, and no amount of highly technical people kicking their feet and holding their breathe and shouting at the communities “you are doing it wrong, you need a highly curated forum where questions are never asked twice” is going to stop human nature.
This seems like a reasonable approach when all actors are being paid to contribute.
I think where discord actually ends up helping is for community projects where everyone is basically a volunteer. It works because it lowers the barrier to helping.
The official documentation of your favorite programming language or highly popular library or framework is probably pretty locked down with a semi high quality bar for contributions. This is a good thing, those docs are consumed by lots of people and the documentation has no context for what the person is trying to do so making sure they are clear, concise, and easy to understand creates a high quality bar.
A lot of projects end up with enthusiastic helpers who probably aren’t going to dedicate the time and energy it takes to become a core maintainer. You can either leave these people and their possible helpfulness on the table or you can harness it with a discord server.
People that might not be the right fit for writing an in-depth general purpose getting started guide are still pretty great at answering peoples questions when given context and the ability to discuss it back and forth. That’s what projects are actually taking advantage of, a large group of people that are willing to help others learn how to use the programming language / library / framework.
The people they help end up having a good time with the friendly helpful community and hang out and help others. If you do it right you get this virtuous cycle where people using the thing you made help each other be successful making the thing you made even more popular.
RTFM, is ok in a corporate environment when part of your paycheck is for RTFMing. But for the last 70 years people that know how stuff works have been shouting RTFM at people wanting to learn how stuff works. But some people just aren’t good at RTFM or plain don’t want to. Discord, and other chat platforms, end up facilitating their learning models.