Anything that comes with the marketing "brought to you by the amazing minds behind classics such as Taco Bell and KFC" should be ringing alarm bells in anyone's minds >.>
Lettuce can be nice, as long as restraint is shown and they don't give you those crunchy white bits.
Onion can add nice flavour, depending on the variety of onion and how it's prepared. (Sometimes it's absolutely acrid and terrible.) Same with pickles.
Tomato is a straight up NOPE. The texture just destroys everything there is to love about a burger.