I don't like the term "hobby" because it carries an implication that the musician isn't serious about it. I'd say it's a "calling" but it's certainly not one that makes meaningful money.
In truth, as I've written many times before, we are coming off the tail of an historical anomaly in the field of professional music performance. A combination of social and economic factors made it possible in the period roughly 1920-1980 for there to be a meaningful number of professional musicians who could earn a living (admittedly, often a sketchy living) from musical performance and closely related work. Before that period, there was a very small number of actual full time professional musicians and the making of music for most people was an at-home amateur activity, almost always unpaid or with nominal compensation ("If you and your brother will come play at the barn dance, I've got half a barrel of salt pork we don't need...") And that's how it's going to be in the future.
One can complain, whine, pi$$ and moan about the state of affairs, but the truth is that it will probably never happen again that a large number of moderately talented musicians will be able to make useful money off playing music. Of course there will be the highly paid pros who support the massive mass-produced products of Taylor Swift, Beyonce, etc,, but those people will be numbered in the hundreds.