Efficiency can be done but it requires disciplines only taught in courses on real-time and embedded programming, and those seem to be fairly rare these days. Real-time and embedded programming teach the programmer how to reason about finite resources like time, energy, memory, and floating-point operations while requiring a level of mastery "down to the metal" that's also rare in overly abstraction-driven programming. RTE skills make every programmer better in the same way that glider skills make every pilot better.