Why Don't Ryanair sell official "Ryanair" cabin bags that meet their requirements ?

Has anyone ever bought one of those scratch cards?

Ryanair aren't a third party in this interaction.

I bought a soft shell bag slightly bigger than those dimensions. I don't cram it full and it easily fits into the template frame at the departure gate. I've never once had an issue with it in 20+ Ryanair flights.

Until you meet a stickler for the rules who breaks out the tape measure and tells you it's too big, doesn't matter that it fits in the sizer, it's bigger than the permitted dimensions, get your wallet out please. I wonder what your response will be when you some smug poster on boards tells you it's your own fault and you need to use the brain you were born with and not to be seeking stupid and impossible etc.

The whole point is that it's not consistent. From one airline to the next and from one airport to the next. Hell, I've seen inconsistencies between desks for the same airline in the same airport taking wheels and handles into account etc. Just because you've always travelled without issue doesn't mean you always will.

Pretending that it's only idiots and simpletons who get caught is all well and good until you get caught out yourself and then what? Are you the idiot? or is it the system that's stupid?