It's all about opportunity cost. You could have graduated a 3 year PA program, started making $140k/year and invested that money, earning 7-10% returns on average.
Here's how I'd calculate it:
Year 4: med student pays $60k tuition, PA earns $140k
Year 5: intern earns $60k, PA starts working overtime 60-65 hours a week, earns $200k
Year 6: repeat
Year 7: repeat
Now.... the PA is $620k richer than the pediatrician.
That $620k of wealth would likely be growing at a rate of $45-60k/year, eventually getting taxed as capital gains which is significantly less than income tax.
So who's better off... the pediatrician working long hours with all the liability and stress earning $220k? Or the PA working 40 hours/week earning $140k with $50k/year in investment income? I think after taxes are factored in, they'll have the same take-home pay but the pediatrician will have shorter telomeres in their DNA