I mean yeah I've come to accept it because I don't know any different. If you can share some examples of large-scale projects that you can compile to test locally near-instantly - or how we might change existing projects/languages to allow for this - then you will have my attention instead of skepticism.

That’s why I write test first. I don’t want to build everything.

This is the reason why I often use tcc compiler for my edit/compile/hotreload cycle, it is about 8x faster than gcc with -O0 and 20x faster than gcc with -O2.

With tcc the initial compilation of hostapd it takes about 0.7 seconds and incremental builds are roughly 50 milliseconds.

The only problem is that tcc's diagnostics aren't the best and sometimes there are mild compatibility issues (usually it is enough to tweak CFLAGS or add some macro definition)

I am firmly in test-driven development camp. My test cases build and run interactively. I rarely need to do a full build. CI will make sure I didn’t break anything unexpected.