My son is patching together a living as a musician. He has had day jobs, but does not at the moment. He plays in multiple bands, plays weddings and corporate events, does arranging work, teaches a bit, and probably a bunch of other music related things that eventually add up. It is not going to make him rich, but it is feeding him and letting him live in an apartment, not under a bridge.
I am lucky in that I like my day job. Music is what I do for the joy of it, not because it has to pay the bills. There are advantages to both approaches.