Many years ago, one of the search options on Google, alongside Images, News, etc., was "Discussions." It would explicitly show results from web forums. I defaulted to this when I was looking for, e.g., product reviews -- because it would bypass the endless SEO spam where someone found some highly-rated products on Amazon and published an article "reviewing" them.

Unfortunately, Google killed that search type. There are some browser extensions and bookmarklets that help, mostly by creating a very complicated search query that looks for specific things in the URL, but the discussion search is something I still mourn.

For what it's worth, my technique these days is to find a forum which has a large amount of discussion, then add a site filter to my Google query and only search that site. For something like product reviews, I can usually find the lesser-known products that don't show up on the SEO lists, at which point I now have a good keyword to find other enthusiast discussions online, which begins to open a lot of doors.

Unfortunately, I haven't quite refined the method for anything other than product reviews. At this point, I've started just using ChatGPT for factual questions before trying Google. :(