No matter what you think, you are never just what your title is. You are always to a certain degree, dipping your toes into other professions. For example, I am by no means a blogger, however, I do enjoy writing from time to time, and as a bonus, it can influence my page rankings on google. So although I am a “drummer” or a “musician”, I am a writer, videographer, producer, marketer and I also dabble with PR. All of these skills are very necessary for me to make it as a “drummer".
If you go to a circus and see a bear, that is kind of interesting. If you see a unicycle that is interesting. But you see a bear on a unicycle, that is really interesting. When you combine things you’re not supposed to combine, people get interested. -Naval Ravikant
Of course, we are drummers first and foremost, and we need those days where we spend hours upon hours in the shed working on our independence, linear fills, and behind the back stick tosses. But if it is all for the purpose of making it as a freelance musician, learning a thing or two about marketing, communication, or music theory, would potentially be as helpful as learning that next crazy fill.