Its pretty clear to me the only things you know about medicine are the words Registrar and Consultant... First off there aren't too many medical graduates coming through, it is just the right amount especially when we take into account the aging population.
Second, every doctor graduating in the UK is guaranteed their first job, called the foundation doctor job. Its only far from home if you graduated bottom of your class or do poorly on your SJT, and this is the same of any degree, its probably safe to say that if you graduated bottom of your class in Econ at LSE and were voted least likely to succeed you probably won't be working at hedge fund anytime soon.
Third, not everyone wants to become a consultant, many want to become GPs, it is a great lifestyle.
Fourth is that all doctors earn quite similar amounts no matter if you obtain a Consultant position or if you become a GP. Generally GPs can expect somewhere between 80,000-100,000 while Consultants usually can earn more somewhere between 90,000-175,000 depending on their seniority and working hours and with bonuses and supplemental income this can be much higher. Those in surgery who work in private hospitals can earn much more although there aren't good numbers on this.
http://careers.bmj.com/careers/advice/view-article.html?id=20000354Either way, most people in medicine go into it because they want to take care of others while also taking care of themselves. Unlike bankers for example even in a hypothetical apocalyptic scenario doctors will still be one of the most valuable professions while bankers will be pretty useless. Also, bankers love to talk about the few who reach the pinnacle of the profession, the vast majority don't make it and unlike medicine this part is actually true. This isn't even to say anything about longevity, to be able to stay in a company like Goldman Sachs is difficult: a common phrase is "up or out".