A member of train staff being bothered to walk up and down the train and check people's tickets isn't being better at the job in the same way that a sales person converting more leads into sales is.
But they kind of are though.
The priorities of my role (at my TOC) as a guard are;
1. Safety - doors, dispatch, etc
2. Punctuality - being on time encourages patronage
3. Customer Service - being visible in the train, available on platforms for assistance
4. Revenue - both sales and scans.
Fail at number 1, I can lose my job.
Fail at 2 & 3, I'll be managed on my performance
Fail at number 4, nothing will happen.
A guard who only does 1 is only doing the basics.
A guard who prioritises 3&4 is putting their job at risk.
A guard who ensures all 4 points are met, but prioritising 1&2 is a high performer.