Communication requires thought and input from both sides - if I use a numeric abbreviation with someone who is unfamiliar with it, I am communicating badly.
I think where we differ is that I see such abbreviations as no worse than any other - TLAs (three letter acronyms) can also be as impenetrable.
What?!?! I have never heard anyone pronounce these terms in such a ludicrous fashion, and it’s not because I don’t have exposure I do a fair amount of work in this space.