yeah there's the part that personally affects me most as a nonbinary service worker--you don't know what someone's gender is by looking at them. sometimes i go more femme, sometimes i go more masc. By going sir or ma'am you might be misgendering someone you never met and making their day worse. this happens to me at least once an hour when on register. i don't think that part will be much news or disagreed on by basically everyone on cohost.
but think about the tone in which sir or ma'am is often said towards any food service or retail worker. sure, its on its face respectful, but its often quite condescending. you know what tone i mean, "excuse me, sir". "uh, ma'am?". People say sir or ma'am to someone they feel above, most of the time, in contrast to its surface level formality. they're talking down to you. hell ive even caught myself slipping and doing this tone to annoying customers. it doesn't help anything