Don't worry, I get what you're sayingI guess what I'm trying to say is that it was a very straightforward move from being a cabin crew on a Thomas Cook plane to being a train crew member. Lots of readily transferable skills and the like. It's not too much of a leap. The barriers to entry are pretty low.
To become a bus driver, the barriers are higher. For a start, 25% of adults don't have a driving license. Then there all the other reasons such as working hours, possibly involving childcare. If it were simply about any job, you'd question why you'd work in hospitality for minimum wage, or in retail when it's so precarious? Why are people working nights in distribution centres for Amazon when bus companies are crying out for drivers at much higher wages?
Sorry if you think I'm being harsh. Really, I'm not but I just think you're oversimplifying it a bit.
You certainly want to become a bus driver rather than because you have to, many want to because of the freedom and you don't have managers breathing down your neck, and that well paid jobs are few and far between in Cornwall
Tho, some want to learn the new skills and do something different, all a matter of ambition really