Two years ago I quit a ~20 year career in networking and frankly I was kinda tired of the industry I was in.
I decided to do a coding bootcamp (I had always been interested in coding). Loved it (found I was a far better student at 40 than 20), and got my first job for less than half what I used to earn.
My pay has risen dramatically and while I don't make what I used to and I'm not as "advanced" in my career as I was... I'm far happier.
A lot of folks seem to see "advancement" as what makes them happy in their job, I worry for them that such things are fleeting and hollow.