#1 Brock Lesnar

Isn't it obvious?
The only reason Brock Lesnar is disliked as much as he is right now and has been for a long time is due to the fact that he is a part-time champion. Beyond that, WWE kept The Universal Championship on him for a whole calendar year and then had him win the belt back at Crown Jewel due to Reigns's sudden illness.
If nothing else, Crown Jewel was supposed to be a crowning moment for Braun Strowman and a chance for WWE to really crack the universal title division wide open, but it ended up being another title victory for Brock Lesnar. It also pretty much guaranteed that the title wouldn't be featured on television, which only had fans even more upset.
In the end, the WWE universe wants a fighting champion and Brock Lesnar just isn't that. He also probably never will be, which means WWE needs to take the title off of him as soon as possible. Fortunately, the company is starting to listen to the fans again, which could mean that the belt changes hands sooner rather than later!
Becky Lynch has been challenged HERE.