Enshittification describes a specific process that is ultimately about maximizing profit for shareholders at the expense of everyone else’s experience. https://en.wikipedia.org/wiki/Enshittification

Mozilla doesn’t have shareholders, neither do most open source projects.

When people give away software for free and yet attempt to make a living from it through other means like ads, that’s a different sorta thing.

Some will still manage to complain that the software they received for free has some ads. Others will ask how they help or donate so that the software can be ad-free.

You do you.