I appreciate your candor and self assessment.
You haven't stated your own background or aspirations but I feel the issue your bumping into is a manifestation of a failure in our academic system.
I have experienced this from the perspective of a student attending an entry level required physics class taught by a professor who was a research scientist.
I didn't transfer classes and attended his class for the tests but attended a much better lecturers class for the normal lessons.
My first professor had research to do, grants to fullfill, TAs to manage, PhD candidates to coach, but due to some policy in our academic institutions a man who might be a brilliant research sceintest is being forced to teach entry level physics when he has no skill as a teacher, which is an entirely different and often non-overlapping skillset from researching, manager, etc.
The idea that we scale teachers based on physical buildings, or the difficulty in grading assignments, or in providing one on one assistance is incongruent with our modern digital communication methods.
In the extreme case a great lecturer can scale to hundreds of millions of people as evidenced by things like MIT Open Course Ware.
In a microcosim this is already happening, teachers assistants are already relied on to do most of the grading, they staff labs where students can receive one on one assistance, and many of the other duties that don't scale and also do not require the skill of a great lecturer.
The thing that bothers me the most is the disservice the process does to students.
Instead of them getting the best quality lecture that allows them to understand and aquire new information with the least friction, they are made struggle with learning from someone who is not adept at teaching, whose aspirations are not to teach, who wouldn't even be teaching the class if they weren't required to, all so that a department can justify the headcount of staff based on the ratio of teachers to students.
Ultimately it comes down to money and how academic institutions are funded. When lecturing is commoditized as a product and then mass produced cheaply (replaying a great lecturer via youtube recording) that completely erodes their business model. They are not acting in the students best interests but in what they think is their own.
To keep your job, not make waves, etc. the other answers are probably better advice.
If you genuinely want to become a good teacher then there is no better way to do it then actually teaching but if that is not your aspiration, only a part of what is required of you so that you you can do what your real aim is, then any way you can lessen them until our academic systems eliminate them for good anyway (great lecturers lecture, great researchers research, etc.) seems like a good idea.
I could be wrong about all of this but it is an area I feel passionate about, criticism welcomed if you disagree.