The problem with the way doc hours are handled is: there's
zero back-up. Whether private practice or group or hospital, everyone is utilized at maximum. I had a colleague once get terrible food poisoning - and had to come in anyway. They
crawled in. We saw them, stole a bed from the trauma surgeons' on-call room, stuck an IV in him, and told him to sleep.
When he emerged two hours later, clinging to his IV pole, we were grateful for the manpower.
That's not counting all of our "unofficial hours". You officially work, whatever, 9-6. You're packed with patients for those hours, though, with almost no time to chart, so you go home and chart ... and on a daily basis at home, you're catching texts from colleagues for informal consults and requests to see patients the next day. Your "off" hours aren't off - and if you have to take call, and end up driving back to the hospital...
EM "handles it better" (a phrase I'm loathe to use) because they have legit shift work, with no continuity. No one calls them for a consult; they're not responsible for anyone after they leave because all their patients are short-stay, they don't have to see "every patient on X roster," they just have to manage their ER while they're in it. They manage shifts because of features more-or-less specific to their specialty. A handful of other specialties share those features, and manage to do the same. But not most.
Hell, I chose to pursue my specialty specifically because it lacks emergencies. I never wanted to wake up in the middle of the night post-residency; no one pays you enough for those hours (you're generally not paid for those hours.)