That mostly works if the owner isn't also the person doing most of the work on the project.

More to the point, it only works if the owner isn't the only person who is willing and able to maintain the project. Open licensing lets you maintain your own fork, but it doesn't by itself grant you the drive, general skill, and project-specific knowledge to do so.

Even then though, you can continue to keep using it as is and not have to worry about them doing some shady updates now that they sold out.

I feel compelled to point out that selling software isn’t “selling out”.

Indeed. And there's nothing wrong with charging for FL/OSS.