Sure, of course individual cases will vary but paying of 500k with post tax dollars in a year would be looking at around 1 million gross, so maybe 0.01% of psychiatrists their first year out of training?
The whole magic of PSLF (and why it's actually a good idea for doctors, even if the goal was more for teachers/social workers/etc), is that you do NOT need to take such jobs that surely sacrifice your patient's health, your health as the doc, or both. You can make your modest payments for 5-6 years after training and never worry about anything else with the loans, simple as that. Easy to budget around, you will still get an effective pay raise when the payments go away, and you can work a job that can be humane and why you hopefully set out to be a physician in the first place.