> your KDE app would have to include the ENTIRE KDE library suite, as well as the QT libraries it's based on, as well as the X window libraries those are based on, etc etc. You'd quickly end up with a calculator app that's hundreds of megabytes.

If you look at the transitive dependencies and then only link in the code that is actually reachable, I doubt that static linking has a significant impact. (I don't know to which degree this is possible with today's toolchains, but I suspect that many libraries have some inefficiencies there due to missing dependency information). As an uneducated estimate (from someone who has written compilers and GUIs entirely from scratch) I'd say 100K of additional statically linked object should be enough for almost any desktop application.

> the linkage to the kernel is also dynamic

Not an expert here, but you don't link to the kernel at all. The interface is via syscalls. At least on Linux, to help decrease inefficiencies at the syscall boundary, there is some magic involving the so-called VDSO, though - which is indeed dynamically linked, but shouldn't be very large either (On my system it seems the [vdso] and [vsyscall] mappings (both executable) both have size 8K. There is also a non-writeable and non-executable [vvar] of size 8K and I guess it links to live variables written by the kernel).