The EM and thermodynamics from 1899 is enough for most of these fields' day-to-day work. Even transistors which are inherently-quantum-mechanical need zero quan

The EM and thermodynamics from 1899 is enough for most of these fields' day-to-day work. Even transistors which are inherently-quantum-mechanical need zero quantum mechanics for their application. You do need quantum mechanics to discover the transistors though. However, there were pedagogical discoveries since then. We have better mathematical notation / conventions / naming for some of these topics that makes them easier to teach today.