I actually use phone for Zoom audio pretty regularly because it has lower latency and higher reliability than computer audio. I recognize that the audio quality is lower, but I'd rather have fewer interruptions and lower latency than nicer quality that is delayed and interrupted. I simultaneously join video via computer, of course.

FWIW, I live in the heart of Silicon Valley, but there's only one ISP available so it's perhaps unsurprising that service isn't stellar.