This has not been my experience - I have known a number of people that were in engineering and were asked to try sales and really enjoyed it. I've known fewer (only one that I can think of) that went the other direction. The best CEO I ever worked with had a real talent for getting people into the right jobs where they could be successful (which solves the "incompetent but nice" problem because "incompetent" is a function of the job they are being asked to do), which was sometimes a very different role than they originally signed up for. People stayed longer and were happier when they were in roles where they could be successful. It is unfortunate that many managers are hesitant to move people into different jobs than they originally signed up for. If the alternative is firing them because they aren't competent, finding a place where they can be successful is a much better option.
People also don’t want to be fired. I think there’s a lot of value left on the table from people getting fired from jobs and getting similar jobs somewhere else that they’re also not great at because they can’t break out of a self image.
It's rare because it is usually illegal if they don't consent to a role change which is out of job description and not clearly a promotion (it's called constructive dismissal, an otherwise deviously clever way of forcing someone to quit instead of having to fire them)
The vast majority of people don't want to have a different job than the one they signed up for.
If you sign up for engineering, you don't want sales. And vice versa. 99% of the time.