It is kind of ironic that we had to wait 20 years to get back what Delphi, Eiffel and co have been offering for decades, in much more resource constrained hardware.

I do not remember best in a class products / technologies often winning a race. It is mostly decided by suits for totally different reasons.

Or free beer stuff, where some developers rather suffer than pay for productive tooling.

Hot reload would still be an improvement on top of fast compile time, but yeah, the most important part is the compile/link part of the iteration.

Saving/reloading state could be done at the framework level, and it can't work in all cases (typically when memory layout is changed between iterations).

But I think that we collectively realized how slow compilers had become only recently (something like five years ago) because it was a slow boil frog situation.

Regardless how fast zig compiler self is, as far as it outsources code generation to llvm and linking to ld it will always be much slower than tinycc. Although recently I've noticed that if you ask llvm to generate and execute something they call bitcode, the code generation seemed faster.