There are doctorates in all sorts of fields including some lightweight fields. I believe getting a PhD in education is nothing like getting a PhD in physics.
A doctorate in a technical field such as engineering, physics, etc is a big deal. I took many masters level electrical engineering courses and got a first hand taste of it. Multiple choice tests with perhaps 5 questions that took 2 hours to complete — (a 0.0053; b 0.0057, etc show your work). The PE exam for electrical engineering was 8 hours and open book - bring anything you want. :-)
I have worked with many PhDs and the ones I have known were usually quite impressive. But we all have different experiences.
Having said all that - Jill Biden’s EdD in education is not much to tout. Her EdD dissertation was “Student Retention at the Community College Level: Meeting Students’ Needs” which is a joke. For her to make a big deal of it is a bit of an insult to those who put in serious effort to attain a PhD in a technical field.
Sometimes it ain’t rocket surgery. :-)