I was trying to say: If all the components in your stack are javascript-based, it makes sense that your RPC-API would also use UTF-16. It wasn't Microsoft pushing it for historical Windows reasons as GP implied, it was dictated by a JS stack they chose but didn't create.
Then I finally sat down to understand enough JS for LLM slop and the having rockets all over the place wasn't just cringe but the quickest way to show you handled utf 16.