Single asterisks in subsequent words should not lead to emphasis

The asterisks and intra-word emphasis issue is definitely frustrating. That said, I would posit that

A×B×C

is better formatting in our unicode-everywhere (or even UTF-8 everywhere) world?

Sadly, many keyboards do not offer the option to enter the “×” character (unless you learn by heart the alt-code). The asterisk is going to be used in the huge majority of cases.

FWIW, many phones have × available under a long-press * and on Windows 10 you find it easily in the pop-up that appears when you hit Windows key plus dot ., which is primarily used for emoji input.

Indeed. However it is hidden away and users do not use it; even though most people are on phones, I never saw anyone use the “×” character.