A counterpoint to that is being involved with a cultural phenomenon such as GoT can contribute towards social skills and makes for easy ice breakers when meeting new people or even going on dates.

It's also just a leisure activity, and if you're caught up with the show, it's only wasting an hour or two every week. You'd be kidding yourself if you said you spend every single non-working, non-sleeping minute of your life developing other skills or "reading useful information".