Dose anyone find it annoying when other gym members are talking on their phone while at the gym?

I have never been annoyed at anyone talking on the phone unless it interrupts a conversation I'm having with them or interrupts timely service they are, or I am, providing. Otherwise, I can't see why people are annoyed with anyone nearby talking on their phone. Is it because you can't hear both sides of the convo? Because people talk to each other in public at the same volume all the time

Very much so.

Why do you care unless they're talking in your ear?