print "HELLO WORLD"

end

now try to tell this AI what you want the program to do - so simple ...

But making many real programs requires specs to define what they are to do EXACTLY - magnitudes more complex - usually with VERY specific details

You have to now put that into some form the AI can figure out - as much work as just programming it in the first place - better to have an AI spot problematic issues - but actually that is not AI - compilers have been doing that for decades.

basic building blocks have long ago been developed (called libraries) but you still had to stitch the components together to do the whole real world task the program was to do.