But you don't need to write against all the layers of crud. You only have to write against the bottom layer, the kernel API. This sort of software would have no need to specifically support "libxml" or "TLS", because that is multiple layers above what this sort of software does.
The flip side is that if you want something like low-level access to your specific graphics card you may need to implement a lot of additional support. But of course nothing says you have to use this everywhere at the exclusion of everything else. There's plenty of systems in the world that from the kernel point of view are basically "I need TCP" and a whole bunch of compute and nothing else terribly special.
[Author of the paper here] You hit the nail on the head, this is precisely what we do (kernel API compatibility) with the LF Unikraft project (the evolution of the 2017 paper) at www.unikraft.org, and kraft.cloud, a cloud platform that leverages Unikraft.
The flip side is that if you want something like low-level access to your specific graphics card you may need to implement a lot of additional support. But of course nothing says you have to use this everywhere at the exclusion of everything else. There's plenty of systems in the world that from the kernel point of view are basically "I need TCP" and a whole bunch of compute and nothing else terribly special.