XY problem confirmed. Thank you OP!

There have been complaints in posts about people asking for advice on which disto to use, that there are too many such posts.

This is a legit concern.Thank you for trying to tackle this!

Provide users the tools to possibly answer the question themselves before creating a post.

Noble. And in its essence, it makes a lot of sense.

DistroChooser is a self-help tool for that purpose.

As a self-help tool it's very bad. Sorry*. I actually hoped that you would mention how it might be used as a basic requirement for anyone that asks which distro to use. The enforcement could be done with a bot which simply scans if any link to distrochooser is present in a post that remotely resembles one that asks for advice on which distro to use. I would actually even argue against this, but I think we might be able to reach an agreement on which questions are actually worth keeping around for further use...

• keep answering posts --> more complaints, possibly silent quitting of community

Honestly, this is better than to limit newbies to strictly stick to Distrochooser for asking which distro they should use 🤣.

• write bot --> I ain’t got the time, maybe somebody has, dunno what the bot would do

I haven't got any experience with building a bot, but I suppose it works by scanning for words in posts. In that case, simply 'flagging' everything that contains the words "which" or "what" in combination with "distro(s)" or "distribution(s)" and ask them to refer their questions to a dedicated Lemmy community in which they can ask would already solve a lot.

• find alternative website --> I ain’t got the time

You don't have to find an alternative website. Nor write one yourself. As it stands, as far as I'm aware, there's simply nothing that satisfies the basic needs for this.

So what do I propose? Relegating these questions to their own dedicated Lemmy community is probably a great and easy solution. If something like a test/algorithm/flowchart/quiz/whatever has to be created, then that one might need substantial effort to get off the ground. However, perhaps comments like these might be helpful as a blueprint.