I honestly can't decide if Wendy's or BK is the worst of the big three fast food chains tbh.
Going just by their food? I'd put Wendy's over BK. I would choose to go to Wendy's if I wanted some fast food, I'd really only go to BK if there were no other fast food chains nearby or if it was a case of 'Well I just ate at the other place a few days ago, I don't want them again'.
But the problem is: Wendy's is the chain where I have had the worst experiences as a customer. It's basically a guarantee that any goddamn Wendy's I go to will end up screwing up my order in one way or another. Just for example, when I got back home from Massachusetts, we stopped at Wendy's to have dinner first and I ordered the bourbon bacon cheeseburger combo and a six piece chicken nuggets. Instead I got their regular ass chicken sandwich combo and no nuggets. I mean, sure I got my nuggets by just going up to the front and saying 'Hey, you guys forgot my nuggets.' but that didn't fix the 'they gave me the wrong goddamn sandwich' problem.
The dude even put in 'classic chicken combo' for my order, so I couldn't have used to the receipt to say 'Hey, this is a chicken sandwich, I didn't order this.' Honestly, if he had input the right item and I'd still gotten the chicken sandwich, I probably would have complained. Like the bourbon bacon burger combo is like $8.50 or some jive like that and the chicken sandwich combo is $5.10 or something, I would have asked them to either make me the burger that I had ordered and paid for or just refund me the difference between the price of the combo I'd ordered and the combo I got because of their screw up.