Is this a good site to get knowledgeable answers to questions or do mostly only lonely people answer?

And what questions do you want to ask? If you search for the best pork tenderloin recipes I can't see what would it matter if the person is lonely or not.

It is as good as any other public site. Depends on the topic and who reads it. You might happen upon an expert or a speculator. It's a crap shoot.
You could probably ask the same question once a week and get completely different results each time.

I wouldn't expect too many knowledgeable answers.

This seems to sum it up when posting questions.

Nope it isn't , you summed it up.

Yes