Why is it that the Mozilla Foundation was set up in such a way that it cannot fund the core browser development activity? Other foundations do fund software dev

Why is it that the Mozilla Foundation was set up in such a way that it cannot fund the core browser development activity? Other foundations do fund software development for their respective projects, e.g. the FreeBSD Foundation [1] and the Python Software Foundation [2]. [1] https://freebsdfoundation.org/about-us/about-the-foundation/ https://freebsdfoundation.org/about-us/about-the-foundation/ [2] https://www.python.org/psf/developersinresidence/ https://www.python.org/psf/developersinresidence/