I'm not that bombastic, but agree in principle with most
You shouldn't use 'C' or C++ until you're totally competent in using ASM.
my take :"You shouldn't use 'C' or C++ until you're reasonably competent in using ASM"

Once you know exactly how to write the entire code set in ASM, you can enhance maintainability by writing it in 'C' or whatever.
maintnbilty, yes, but what's equally important is coding productivity. I can write a module in C many times faster than in asm. Does that mean I do not use asm?, heck no, if a module s critical re throughput it is n asm.

HLL's are OK for machines with GB of memory and PB of external storage, with GIPS of performance, though the HLL's are nearly always a guarantee of introduced bugs and inefficiencies.
i wouldn't know about "introduced bugs" I will not make a call, but think they are less in C than in asm. Re inefficiency, who cares for uncritical routines.

With an HLL compiler you're just introducing another level of uncertainty.
Richard, the word is not 'uncertainty' but 'abstraction'.

Once you attain enough familiarity with the MCU and the compiler to reduce the uncertainty, you know enough to write the ASM better than the compiler can.
absolutely, and you should do so when it matters

not pantyhose

Erik