It's not just Reddit. It's all of social media.
I think the fundamental problem is that if you're sitting somewhere bored, maybe at work, maybe elsewhere, you can consume some media about a hobby, and you can make an online purchase of some gear for the hobby, but you often can't actually do the hobby.
It's dumb, but I will catch myself watching a ten minute video on synthsizers while I'm at work, but I would never whip out a synth and spend ten minutes playing it at work. But it's the playing it that actually satisfies the desire. Consuming media just increases it.
It's a dumb loop but it's really hard to get out of because:
1. The activation energy of doing a hobby is always higher than the energy required to just consume media about it, or even buy gear online for it.
2. We're often in environments where it's impossible or inappropriate to do the hobby (work, in line at the DMV, etc.) but where we are able to consume media or make purchases.