The way I think of it, you can be miserable and overworked in any job. There are many careers out there which face the same key issues: long hours, heavy workload, annoying bureaucratic/administrative hierarchies, and so on. Medicine is unique for its job responsibilities and training but not in the sense that it is the only career where people face burnout.
I’m not defending the issues you outlined in your post; I hope that our generation of physicians will enact real change in all avenues, starting with the application process. But change can be slow and nonlinear. A major part of burnout can be attributed to how demanding a specialty is, caseload, etc. So your personal choices as to what specialty you pursue can make a difference too.
And of course, disgruntled people will always speak the loudest. This is why I try to stay away from the med school/residency reddit. I know of many physicians IRL (my boss/mentor included) who lead very happy and fulfilling lives, whatever that means to them personally.