Java can also have 15+ minute cold compiles on large projects if you kill all caches. It's less bad on smaller codebases because you don't have to recompile dependencies if you target a bytecode vm, but if you always gate feedback on a cold compile in a fresh VM you just aren't gonna beat an interpreted language

But I'd look at people a bit oddly if they said: 'We didn't want to set up CI caching and compiled languages took 30 minutes per run so we changed our entire codebase to python'.

Maybe it makes sense for them, and caching across dynamically spawned VM's is admittedly a harder problem which most build systems aren't great at, but still. I can easily believe that getting build caching to be reliable would be a lot of work, but is it more work than a full rewrite of a significant codebase?