They’re still waiting to be mainstreamed into the kernel. The process of integrating drivers into the kernel is complicated. Coding practices of the coder that wrote the driver play a large part in that. Buggy or badly written code will not get accepted. Not all of these drivers have the code quality that is required in order to be merged with the kernel.
Why aren’t these drivers installed by default yet
They’re still waiting to be mainstreamed into the kernel. The process of integrating drivers into the kernel is complicated. Coding practices of the coder that wrote the driver play a large part in that. Buggy or badly written code will not get accepted. Not all of these drivers have the code quality that is required in order to be merged with the kernel.