Their internals are just as relevant (now even more relevant) as any other technology as they always need to be improved to the SOTA (state of the art) meaning that someone has to understand their internals.

It also means more jobs for the people who understand them at a deeper level to advance the SOTA of specific widely used technologies such as operating systems, compilers, neural network architectures and hardware such as GPUs or TPU chips.

Someone has to maintain and improve them.