Heck last year I paid out of my own pocket to take the two introduction to VMware classes, despite working with VMware 2006. Why did I take the classes. VMware has come out with a lot of new features in the past 5 years and I have not been able to use them all professionally. Also in taking the class I found that some the limitations that existed in earlier versions of the software no longer existed. I had no idea that I was no longer following best practices. Plus there was the stuff that I had flat out forgotten along the way. It was well worth the $400 that I spent.
As long as they are asking you to do this during working hours and they are paying for it, I don't see why you are so upset. You say you are at minimum competent with the skill, maybe they are wanting to make you into an expert in the skill and part of that is getting you the extra training.
It's just another...aggravation in what seems like a job mismatch - role, expectations, etc.
I'm not keen on it for at least a couple of reasons, not the least of which is because....I've seen said skill demonstrated at the company, and I'm not impressed.
And it's just me that is required to take the course -- i.e. they seem to truly believe I'm not competent/enough in said skill.
Were I a different person I might think, "Cool - I get to brush up on tying my shoelaces", or "Cool - a couple of free hours", or similar, but I'm not a different type of person.
I didn't push back (yet) on this particular topic because previous pushbacks on various issues did little or nothing, and I've been job hunting already.
There is a 5% chance I could end up staying, so curious how others have dealt with 'getting nephewed'.
My employer made us all take a course in "diversity and inclusion" which I think was OK because it was based on leadership principles the organization has been pushing for a long time and avoided the excesses of that sort of thing.