here are some "articles" on the subject:
https://www.bmj.com/content/373/bmj.n1594
https://www.beckersasc.com/benchmarking/22-of-physicians-con...
https://www.medpagetoday.com/practicemanagement/practicemana...
And one of these articles (the last) is from 2013, talking about a change in healthcare practices (corporate unification), the ACA (limits on accepting medicare patients) and the health reform law (liability reform). So, I guess medical burnout has been coming log before Covid and we have just been ignoring it?