Health economics is complicated. The primary barrier to more health professionals in most economies is government funding followed by restrictive practices in the industry certifying new entrants, not that the certification per se is wrong, it's the controls on rate of certification outcome which are the problem: doctors don't want dilution of income. The hours suck but the money is good.
They definitely need to work less, especially junior doctors and registrars in hospital. The hours are dangerously insane, life threatening for doctor and patient alike and it's no different in nursing: there's a reason nurses go locum and supply over contracted and it's bound up in stupid health economics.
(Not in medicine, I read this. Happy if people in the field correct me)