Is worrying about crap like this more or less worthwhile than playing video games? Seems like you say it's less worthwhile (and apparently feel strongly about that), but that's a judgment call too.
Yes, you can use your free time however you like. It's still a decision everyone needs to make, somehow.
But do it based on what you want and what you value, and let others do the same.
Wasting time being concerned if someone else thinks what you're doing or reading or playing is important or valuable is a silly waste of time that could be better spent actually living.
Totally agree that you shouldn't be much concerned about what other people think. (Especially on the Internet.)
I don't agree that thinking about what you want to do with your life is a waste of time. I also don't think you need to decide on this alone - talking to other people about it seems quite okay.
Yes, you can use your free time however you like. It's still a decision everyone needs to make, somehow.