This will be short and sweet for those that don't want to read a bunch
Food Wars is 8/10 up until Chapter 263 (YOU CAN STOP READING HERE AND IT WOULD BE MUCH BETTER THAN MOVING ON)
Food Wars is 4/10 after Chapter 263.
The only way I can describe this is that, pretend you are playing a video game where the hero gets all sorts of equipment and powers and defeats the bad guy. HOWEVER, they make a sequel and in this sequel in the starting stages, the hero is stripped of all the stuff they got in Game 1 and they start from scratch. This is basically what happens on top of just butchering Erina's character.
It just seems like the author was done with the series after the finale of the Central arc and some light research confirms this, sadly.