Its only been a few years that trainees are being paid.
Engineers also take up private work
Number of doctors in west is regulated, each graduate is guaranteed a place for training, actually there are more training jobs available in west than the number of their medical graduates, thats why you have foreign graduates filling up the posts.
Why people still apply for medicine, i don’t know, i will not put my kids into medicine. Its a highly stressed job with long working hours, continuous training. Money paid is not worth the effort doctors put in.