Plenty of companies including every one I’ve worked for maintain their own forks of open-source software, often while waiting for maintainers to apply patches.

Plenty of companies including every one I’ve worked for maintain their own forks of open-source software, often while waiting for maintainers to apply patches. I’ve also contributed patches upstream to open source software plenty of times and the majority of time the maintainers have been willing to accept it. Tons of Linux distros maintain their own set of patches on top of loads of software to make it work better with the rest of their system. Sure, there are examples where it’s infeasible to change things but in practice it’s a lot more likely than with proprietary software.