When I was younger, I asked my dad why anybody would ever take up smoking. Everyone knew how unhealthy it was, after all.
He said that even though people knew it was bad, they also thought it was worth it to get a temporary pleasure. I had just spent half the day messing around on a Pokemon website, and he pointed out that I was doing pretty much the same thing by playing online. I was making whatever goals I had for the future less likely to happen because I wasn’t pursuing them.
If you want to be a professional writer, every second you spend doing other things (that aren’t necessary) is a second taken away from the future you want to have. The same thing goes for if you want to be a well-known fanfiction author, a great roleplayer, or any other writing-related thing you can think of.
Just something to consider.