Two of the many people I know that tried to make it are my sister and her husband.
My sis did generate some label interest but because of her commitment to becoming a Dr she decided to finish school and pick up the music career afterwards.
By that time she had "aged out".
My BIL started to write "canned" tracks, jingles if you will.
Turned out to be a good move. He started getting what he calls "mailbox money". He comes home and finds royalty checks from all over the world in his mail. Sometimes it's a couple of hundred bucks, other times thousands.
This led to him landing a gig with TLC. He currently does the music for the tv show
Jon & Kate Plus Eight.
There are plenty of ways to make a living in music. Being a performing act is only one of them.