As the author mentions Fractional CTOs, I'll chip in with my experience in that. I'm currently a Fractional CTO, which is a great way to say that you are specializing in being a generalist ;)

You need to know enough about all aspects of running a software team that builds products. Not many people are such generalists and when companies need that skillset, they pay a premium for it.

It's a way to do really interesting work and if that's not available, it's easy to pick up some senior engineering stints in between.