There were some gross injustices back in the 1980s concerning paying for meals in an Officers' Mess...
Bean stealers who paid little, if anything.
The Stn Rock who ate an enormous breakfast, but paid the same as a dainty little WRAF did for her two pieces of toast.
The nonsense of 'extra messing' - if you had 3 meals in one day you paid one day's extra messing, but if you had breakfast one day, lunch on a second and dinner on a third, you paid 3 days extra messing.
'Duty meal' entitlement - very divisive that was.
Then there was the 'Admin Wing Lunch', so named because Admin Wg officers who lived out would enjoy a huge lunch at the expense of living in aircrew who weren't able to get down to the mess at lunchtime.
Pay as you dine was supposed to make things fairer for all. The simple concept being that, as in any other restaurant, you paid for what you ate. But it was hijacked by the decision to introduce contractor catering - THAT was the real nonsense. Because contractors expect to make profits, so prices went up, variety and quality went down.
Don't blame PAYD, blame the creeping cancer of contractorisation!