I think arguing that assembly is an abstraction is going the wrong direction on why it is hard. Assembly largely forces numerical abstraction on your problem.

I think arguing that assembly is an abstraction is going the wrong direction on why it is hard. Assembly largely forces numerical abstraction on your problem. Which is a lot harder to reason about than folks want to acknowledge. That is, higher level languages let you get farther away from the abstraction that is the computer itself. As such, you can have a less abstract program in a language that has higher abstraction away from the execution environment.