Agreed. With Animal Crossing there needs to be a simplicity to the features. Not so simple like it's a clicker phone game, but kinda like feng shui for game design – not too crowded and cluttered but instead streamlined and calming.
I wouldn't want too elaborate of an energy system. I am a little surprised with the one they've put in already, where it seems like eating a fruit gives you 1 energy point and you can accumulate the energy points, then use them on hard tasks. But I like that better than an energy bar that depletes to empty. I'd imagine that, perhaps, eating a foreign fruit might give you 2 energy points, for example, instead of the native fruit which gives you 1.
I wonder though if Nintendo wouldn't want to put in a cooking system because they have an idea of promoting a healthy active lifestyle with their products and don't want your character to be consuming cakes and bonbons every day XD If that's the case, the perfect way to balance it (and the concerns Winona mentioned) is for unhealthy cooked goods to not give you stamina, but make nice gifts. (Fruitcake anyone? lol) Meanwhile, healthy cooked meals can give you more stamina points than eating a raw apple would.
It would also add a bit more challenge to doing requests for villagers. Rather than just bringing them a fruit from one of your trees (kinda boring after a while), you have to gather a few ingredients and craft them a food item. That would also help you discover recipes, by getting requests from villagers.
TLDR: So basically, the main focus of cooking would be: (1) decorating your home (2) giving gifts to villagers and adding more challenge to fulfilling their requests to make it more fun (3) healthy cooked meals would give you more stamina points than the native fruit does, since that stamina point system is already in the game