Yes, I only visit reddit when I have only have something curious about, I don't actively scroll through it, maybe a few minutes when I'm on it. That's healthy boundary.

As for Hacker News, there is https://hackernewsletter.com/ that sends you mail of the best articles on startups, technology, programming, and more. All links are curated by hand from Hacker News. Join 60,000+ other subscribers and don't miss another week.

They also offer daily mails, but I'd say avoid it.

Easy way to discern if site is social Cookie Clicker: 1.Does it provide a rating/score for content. 2.Does it reward users with larger rating/score? 3.Does it limit users with lower rating/score? If all three question are positive, then it is optimizing for content-score engagement type of users, pushing the lever for extra dopamine hits.