Yet we can have the CAA listing every route out of the UK so all and sundry can spot how airline X is doing on a YYY-ZZZ routing regarding passenger numbers.
Having that sole metric alone is not an indicator of how profitable the route is, though actions speak larger than words if you see an airline, particularly a low-cost one, pull a route.
Just look at the Manchester thread where you can typically see 4 airlines singled out as they are the sole operators on the long-haul route they operate on.