Some examples of some great subs:
- HomeImprorvement is great for repair advice
- Keto was helpful in my weight loss journey
- Posture for, well, fixing my posture
I've also bought and sold various digital and physical goods through HardwareSwap, GameSale, SteamGameSwap, and others. One of Reddit's strengths is being able to tie a username to a post history across many interests, which has given me enough confidence signals in buying and selling things on there. I'm sure fraud happens, but I have personally not (yet) been affected by it when transacting on the platform.
But the main, core "Reddit experience" as algorithmically produced by r/Popular is a complete dumpster fire. It's the noise of the entire internet, jam packed into a webpage. So many low quality posts and comments that encapsulate all the negatives about "internet culture". There's no room for thoughtful discussion and discourse on the majority of the site, just shitposting and low rung commentary.
Because of that, having a productive/net positive Reddit experience comes with a high barrier to entry in knowing which communities to pay attention to and which time sinks to avoid.