if you mean university, then should everyone also be forced to indentured servitude until they pay back their university fees?The cost to train a doctor from undergraduate level to foundation level is at least £230,000. And that figure is 7 years out of date.
what about those that immediately go into the private sectors?
if you mean after university, it's called a salary for doing a job. there's very little "training"
nearly all "training" is done after working hours in own time, and exams/courses etc is paid out of pocket (mostly)