Huge numbers left in the days before degrees according to Mrs R - she reckons at least half her set quit after they qualified, mostly to get married and have kids. But with their nursing qualification so they could go back to it.The reason they introduced degrees was because more senior roles in nursing required more education. You're not getting to be a clinical nurse manager or theatre nurse these days without a degree level of education. The days of nurses being treated as low paid ward skivvies are well over. Young nurses got fed up being treated like dirt by admin and doctors and huge numbers left nursing. A degree brings more opportunities and more respect.
As for degrees required at senior level, most of her nurse-y mates don’t have degrees, have no intention of getting a degree and they’re all Band 8 or the equivalent. More senior than that and you’d think all nurses are male.