It's also not like I message my boss before walking to his office, that doesn't make every time someone walks in equally urgent. Sometimes it'll be me asking about lunch, sometimes it'll be the firefighters.
I agree a priority button would be nice when calling someone, to be able to differentiate, but how often do you get interrupted by a phone call during something that you didn't want to be interrupted? For me it's never so uninterruptable that declining the call was an issue; I decline calls maybe twice per year (on a total of maybe a dozen unexpected incoming calls altogether). I'd prefer if it's okay to just pick up a phone and see if someone is reachable.
