You spend six years (more or less) at university, racking up debt. Once you graduate, you spend two years as a "F1/F2", where you basically get bullied and do clerical work. Once you've completed these two years, you can apply for specialist training.
You are working 60 hour weeks doing 1/4 night shifts (if you're lucky) and 1/3 weekend. Not only that you move hospital every six months. in london this is kinda feasible, else where it means a 2 hour commute. The starting wage for an F1 is £24-36k
After the first two years you can apply for specialist training. However the attrition rate is horrific: https://www.bmj.com/content/364/bmj.l523.full loosing 64% of your trainees after 8 years of training is just pathetic.
Some of this is government based, but a lot is the medical establishment being utter shits. bullying is rife, the "leaders" have a lot of "I managed it, it didn't do me any harm", there is no incentive to change because everyone rotates every 6months, so why bother putting effort in?