If you've been online for any length of time, you've struggled with the question of how much time to spend on social platforms. You weigh the pros and cons and perhaps miss the central point-- sharing information of any kind potentially adds to the value of the Web as a whole.
If your expertise is freely shared by posting something interesting you have made a contribution. If you think of it that way, perhaps you'll waste less time on trivia. Or you won't. Either way consider it as your effort to teach something to others.