The issue you raise is one of agency and expectations. Professional development is something done TO a person. Learning is the the consequence of actions taken by the learner. PD is a treatment model, usually designed to be as modest, inexpensive and unambitious as possible. It's often based on getting teachers to do something against their self-interest OR trivial.
One of the reasons PD "doesn't work" is that it is almost always outside the context of the practice. The most effective work I've done in schools is when I work in classsrooms with the teacher and her students.

The expectations of PD have been lowered consistently in nearly every respect over the past 25-30 years. I used to work in schools for months and teachers would enroll in 12-week workshops or two-week residential institutes. Today, PD is most often an hour of schtick.

There needs to be an expectation that teachers continuously develop expertise even when not reminded to do so. Schools need to expect that prodessionals develop and provide the resources to support that.