But you are back on Reddit in the meantime, and they know that even small engagements are what start to bring people back. It’s like smoking cigarettes, it only takes a few to fall back into the habit. Suddenly your popping by your old favorite communities to check in on things and blah blah blah slippery slope.
Just don't give in to any temptation and it's fine. If you're going, you're contributing to their traffic and hence to their value proposition to advertisers whether you click ads or not.