Machine code is less portable, as new CPU optimizations and instructions are released, its easier to update a compiler to integrate those in its optimizations than regenerate and retest all of your code. Also, if you need to target different OSs, like windows vs MacOs vs Linux its easier to make portable code in something higher level like python or java.

Static analysis to check for things like memory leaks or security vulnerabilities like sql injections are likely easier to do on human readable code rather than assembly.

Its easier for a human to go in an tweak code that is written in human readable language rather than assembly.