Personally it's life-wasting in the manner that I use it as an outlet to avoid boredom, but the value I get from it cancels it out. I think it would be better for me to have a set period of time to catch up on valuable online communities, rather than opening it whenever I get bored/have free time.
I feel like I actually learn and gain valuable insights (such as posts like this) more than not. Considering there's no endless feed, I don't find it addictive in the same way reddit or twitter is with their algorithm aggressively showing you content that screams at you to engage (mostly negatively)
Checking HN once or twice a day is fine. Checking it over and over is not. Just like any other social media. Reddit isn't an issue, it's checking it over and over all day long that's the problem.