We've been to FW many times and never purchased a dining plan. We bring a suitcase full of dry food and then get groceries delivered to the Fort. We either rent an RV or a cabin, and either way we were able to have groceries delivered ahead of time so we arrive to a full fridge.
We cook breakfast and dinner and pack lunch. Our kids are little so we get an early start to the parks and are generally back around 6 PM.
As an adult I will admit I get tired of PB&J and granola bars for lunch every day, but the dining plan pricing makes me cringe. Not that we can't afford it, but these trips are expensive enough without getting gouged on food. And frankly when we've met friends for quick service or even sit-down meals I've been underwhelmed for the most part.
I never understood staying at the Fort and then going in on the dining plan.
We do try to go to Trail's End for breakfast once per trip.