Recently I've been air-dropped into such a legacy project at work in order to save a cybersecurity-focused release date. Millions of lines of open-source code checked in a decade ago prior to the Subversion-to-Git migration, then patched everywhere to the point where diffs for the CVEs don't apply and we're not even sure what upstream versions best describe the forks.
By the end, the project manager begged me to turn off my flamethrower, as I was ripping it all out for a clean west manifest to tagged versions and stacks of patches. "Take it home OSS" is like take-out food: if you don't do your chores and leave it out for months or years on the kitchen counter, the next person to enter the apartment is going to puke.