One of the most useful advice I got (forgot the name and the link) is to never got further than two replies deep. Every time I broke that, in hindsight, it was dumb to do so.

What did you find dumb about it?

The mind loves to invent time regret in hindsight: "I should have cleaned the house instead of watching TV", "I should have spent more time with my kids instead of spending so much time at my job", things like that. Is that what you mean?

This is probably correct the instant you get a whiff of bad faith or differing fundamental principles that you aren't going to be able to change, and if you do try, it'll devolve into an argument, but I've been involved in significantly longer threads that were just people asking for advice who had a lot of questions that weren't easily answerable with a google search, as well as deeper discussions that were genuinely made in good faith and made me question some of my assumptions. The latter is quite rare, but they certainly are a thing.

"A rule that is almost always valid: never refute or answer a critic, no matter how preposterous the criticism may be. Do not let the critic teach you the cloth, as they say in bullfighting circles. Never charge the cloth, even if the critic resorts to actual misquotation."

-- William S. Burroughs, "The Western Lands"

I guess it depends on what you're there to do. Sometimes I want feedback on a thought that's hyperspecific.

I could wander around town and strike up conversations with strangers and years would pass before I found somebody with the specific set of interests. But there in the depths I can find somebody else who is actually looking to talk about the same niche thing.

I don't know if friends is the right word, I only rarely meet them again later. But for a brief time we were a some kind of partner.

I’m making a mental note of that.