Could be that the lead cooks or chefs have moved on?
I know of two local places where that is exactly what happened. One is a "Comfort Food" diner joint and the other a Chinese place.
The diner slumped for a bit but whoever the replacement is now is cooking well, but a bit slow. I'm never in a hurry though. Short order cooking is not easy.
The Chinese place the food was so bad I'll not go back.
