But that doesn't mean nobody should see a therapist. It isn't all snake oil.
A good therapist can help you identify where you need to get to for your own sake, and what skills will help you get there. They can help you realize when you're putting stumbling blocks in your own path and figure out how to stop doing that. They can help you pick out goals, point you in the right direction, and sometimes offer some help getting started on the way. The rest is up to you, of course.
You don't have to be mentally ill to benefit from a therapist's help. In fact, I think you're likely to benefit more if you're basically pretty healthy than if you're not, simply because you're more functional, and therefore better able to make use of what you learn.
That's my perspective from having seen a therapist for a while a couple of times earlier in life, from having encouraged my offspring to see them at difficult moments, from having a friend who is a licensed clinical counselor, and from having gone to graduate school in clinical psychology before I became a programmer.
Caveat emptor, of course. There are good therapists and there are charlatans. Look carefully and use common sense.
Mental health professionals are available if you or your partner would like to talk. Therapists would be a better place to start than jumping to a psychiatrist and medications. Definitely don’t try to get ADHD stimulants and power through burnout in a job she hates. That would make burnout exponentially worse.
If your partner decides to try therapy, it can even be done over video calls now. Depending on insurance the video therapy is often quite cheap, too. Of course, it’s up to you if you want to pursue that route. I agree that jumping to specific diagnoses based on a few sentences of your question is inappropriate.
Some people hate working, period. And the kind of job that's fun or engaging for you might not be available to you. For the overwhelming majority of people, their lot in life is to toil at something they'd rather not be doing. But normal people are able to put their heads down and get it done. If you can't and it's causing problems in your life, that's something you should see someone about. Finding a more enjoyable job might be part of the solution, but remember that such options are often a luxury of the elite.