>everybody felt they’d need a training course.
in my experience there might be a few people for whom "the icons are different, i need a training course" is a legitimate concern. but for the vast majority of workers, it's not "i need a training course" it's "i feel like i can get away with demanding a training course" with the full knowledge that asking for a training course will derail the effort to make a change.
I find that people who demand or complain about training tends to be a really good filter for people that are hard to work with or intellectually incurious.
That's exactly what I've said when someone has suggested moving away from my favorite tool to their favorite tool. I've literally said "Uh, don't forget, we'll likely need an 8 hour training course for a dozen engineers.", saw the numbers crunching in the PM's head and then they'll say "Maybe we'll circle back on moving to X, I'll need to request more funding for next year."