Eh. Compilers are only worse because we don't care. Optimal register allocation + spilling is easily doable now on today's machines/algorithms. We just don't

Eh. Compilers are only worse because we don't care. Optimal register allocation + spilling is easily doable now on today's machines/algorithms. We just don't bother because it's not truly worth it in most cases (IE we get most of the performance for a very low cost)