Ask HN: How do you search for discussions on a topic?

I notice that I'm constantly struggling to find discussion on a particula topic, rather than the topic itself.

Unless you know a number of places to specifically search (for example doing a "site:reddit.com/r/subreddit my topic") it seems that Google rarely organically throws up discussions from forums etc. on a particular topic. This is no doubt by design and has changed over the years.

I'm not talking just about acedemic or technology topics, this could be anything. Usually when I want to buy something or go somewhere, I want to find information and recommendations from other people. For example, campings spots in a certain place, good used car dealers in an area and so on.

Is there any search engine that prioritises these searches, or are there any techniques that can help?