Hand-written assembly is still the king when it comes to maximising CPU performance. You can see that most clearly on older machines, but the potential is still

Hand-written assembly is still the king when it comes to maximising CPU performance. You can see that most clearly on older machines, but the potential is still there on newer machines too. I'd suggest that there's a chance of a small resurgence in assembly after Moore's Law has truly bitten the dust. Also, despite being very verbose, it's actually very easy to reason about. That's because you've removed all the layers of abstraction found with higher-level languages that are involved in translating source code to machine code. In assembly, your computer has to run the algorithms in the way you designed them, as it's necessary to spell out in exact detail how the algorithms should run. There's still layers of abstraction available through subroutines and macros, as well as comments for describing what the code does. The issue with assembly isn't with clarity per se, it's with portability and verboseness. Every part of the program has to be written out in painstaking detail, and the work involved in porting to a different architecture is much more than with languages like C.