> Maybe there is a startup idea here, in making it easier to manage and patch third party dependencies, like how of the big tech companies do?
It's most often not as simple as "patch third party dependencies". The Linux kernel is quite infamous for having so many refactorings and reworkings that you can count the amount of proprietary drivers for current (!) kernel versions on one hand. IIRC, the only one viable at the moment is NVIDIA's weird shim, with the longest other holdout Paragon NTFS having gone for open-sourcing a couple weeks ago.
Everyone else (cough Android or general embedded PSPs/BSPs) is stuck with fossilized kernel versions. Take apart any cheap router firmware and you'll likely see a 2.6.x kernel and even older u-boot versions since no one wants to do the work necessary to port over all the custom cruft to a modern version, and no one wants to commit stuff upstream as the Linux kernel maintainers won't even think about accepting the shoddy quality that is common in the embedded space, not to mention people being afraid of violating NDAs.