Although McDonalds is pretty good the french fries in burger king are much tastier and so are the nuggets. Also the McDonalds nuggets aren't that good anyways. The sauces are taster in Burger King especially the barbecue sauce. Although Burger King is better it isn't the best there are much better fast food joints.
There are better burger joints, including Mighty Fine in Austin, The Ground Patty in New Orleans, BurgerFi, The Ground Round... High end burger joints that typically have gourmet burgers and alcoholic beverages in addition to soft drinks. When it comes to the basic fast food burger epitomized by Burger King and McDonald's (and also Sonic and Wendy's), convenience is probably a key consideration and non-burger items on the menu. I know my kids love McDonald's, but they never buy a burger, preferring chicken nuggets or chicken sandwiches. The other consideration for families with kids, might be the toy that comes with the kid's meal and McDonald's has always been king. McDonald's also has the best fries IMHO. But when it comes to burgers, BK rules. I would rather have a Whopper with cheese any day over a Big Mac or a Quarter Pounder with cheese or even a Home-style with cheese. In an ideal world, we could have BK flame-broiled meat patty on a Sonic bun with Sonic condiments, especially their mustard and onions, and McDonald's fries!