I recognize that Linux and especially GNU are bloated. However the Linux LOC overtime chart is useless at demonstrating it. AFAIK size increase of Linux is mainly caused by drivers. Device support is overall the most important thing OS offers. And it's hard to be small and elegant while supporting everything under the sun, which Linux can't even really achieve. One could say something about epoll instead of kqueue, ALSA instead of OSS or other similar cases. But the size itself doesn't say much.

I agree that there is much to be explored yet in OS design. However it needs deep pockets to actually support wide array of hardware. Or a long time.

I cheer for Toybox and Oil shell regarding the GNU userland.

When I see all the openat(2) and friends family of functions or chmod/fchmod, chdir/fchdir, barbaz/fbarbaz I'm thinking that it all needs a bit of a clean up. Some batching system call would be appreciated as after Meltdown syscalls are more expensive.

I personally like and keep my fingers crossed for DragonflyBSD. They are doing things that are innovative while keeping conservative core for the lack of better words. But at the same time DragonflyBSD has minuscule hardware support comparing to Linux.