My comment, or Ace's?
Why should I have a desire to move to a job field that has effectively the same wages as mine. I wouldn't start at the same level, I would lose money until I gained the experience for the way those parts are put together.
"Parts is parts."
Most things I have worked on in different jobs were the same types of parts, put together differently. I have entertained the notion of working on Hospital equipment before, but I prefer to stay fixed. For those who like to travel, it's better for them. Just not for me, to lose money, be able to make the same later, and deal with travel.
I like being "fixed station," rather than roving service.