Good take - defining a "low-level language" feels like trying to define a "cold temperature". It's all very relative.

We could say that a temperature is "freezing" if it is under 0C, and "boiling" if it is over 100C. But it's hard to nail down "cold" or "warm", as any group sharing a thermostat will tell you.

You can easily place arbitrary assembly commands or memory values in C code. Plenty of embedded codebases are littered with asm blocks in performance-critical areas. It's hard to see it as a high-level language in the age of javascript/python, but maybe the overton window has shifted.