You don't think it has any impact? Even on the margins? I think it's basically expected that musicians will give up some day and join the working world, in part because it's so hard to make a living in. If it's harder to make a living -> more people give up -> less music. If it's easier -> fewer people give up -> more music.
It’s not a question of whether it has no impact or not because that’s irrelevant. You would actively have to punish people for making music in order for music not to be made—that’s how strong that force is. (Well heck, maybe more music would be made in that case, out of spite and rebellion.)
No music at all is not the concern, music you like not being made by artists you admire is the concern. This is basically the entire premise of Patreon btw.
So surely there would be also some gifted people who happen to have the luxory to focus completely on the music they want to make, but those would be the exception.