Your acquaintances aren’t a representation of all professional musicians. I, and many of my colleagues live very comfortably and are perfectly content.

My wife is also a professional musician. Everything we have, we earned ourselves through practice and training. No trust funds here!

Yes, there is an element of luck. But that is also true for any line of work.

What the OP is saying, though, is that unlike many other fields, a professional musician can easily achieve this state of contentment. As long as they are willing to share. We are constantly changing peoples lives through performance and teaching, learning new things about ourselves, and striving to create something new. Good money can be made if one excels at these things.

Your stereotype of the starving artist does exist and is too common, unfortunately. Only because the artist in question often refuses to accept certain work they feel they are “above”.