It's no accident that Apple chose a yellow icon for its walkie-talkie feature. I dug out my old (2002ish) Nextel with PTT (push to talk). It was all the rage back then... :
Walkie talkie Nextel cellphones... there's an entire generation that doesn't know about these lol : r/nostalgia
TOAN MAGAZINE — Throwback Thursday: Nextel/Boost Mobile Chirp...