Ha, author here -- I'm probably a member of this group myself. I bootstrapped my first company and then ran a small consultancy for awhile.
Spent some time at a fund, but we primarily bought and operated SaaS companies as cash flow businesses. It's been base hits all the way.
I think if you're happy with building a business that gives you freedom and work life balance, this can be a great life. Personally, I eventually got tired of consulting even though it was good money and lifestyle. There were other things I wanted to work on that I didn't have time for, and I wanted to create something of my own, rather than just working on other people's projects.
But that's just my experience--I think if you're happy in the freelance / agency life, it can be great, but you are still ultimately selling time for money. Maybe this is a 4th path, the career craftsman--working a job you enjoy with people you like, and not needing your work to be as aligned with a "passion" or some sort of calling.
Just my $0.02 -- appreciate the comment and will have to make my writing sound less like an AI in the future ^_^;;