I just discovered that after you do the daily challenge in Crypt of the Necrodancer you can go to the leaderboards to see how other people did, and then watch replays of their runs. I just spent 30 minutes watching the current leader do an amazing 4000+ coin run.

This would be even more of a time suck but thankfully(?) there doesn't seem to be a way to save or share replays, even within the game itself.