It must indeed be very frustrating for the crew. Unavailability of hot meals especially on longer sectors is totally unacceptable, a small quantity of the cold salad option should be loaded over and above.
The solution to the issues mentioned is simple- at online check-in, a main course selection should be offered with meal ratios catered appropriately on the day(similar to the ex-LON pre-pandemic option in WT+) Re the lack of Champagne etc, there is obviously a requirement for additional supplies on high-load CE flights.