#2 For Lesnar to have a different type of match
Say what you want about Brock Lesnar, but he's one of the best in the ring with a variety of wrestlers. In the last two years at Survivor Series, the current WWE Champion has faced smaller wrestlers, including Daniel Bryan last year and AJ Styles in 2017.
This year, for the third time in a row, Lesnar will face off against a smaller wrestler in Rey Mysterio. Mysterio is a completely different wrestler to Lesnar's previous opponent, Cain Velasquez, which shows that Lesnar wants to showcase his different skills in the ring, and perhaps show a different type of match to his fans.
One thing is for sure, Lesnar and Mysterio - two wily veterans - will put on a fantastic match, and some old-school storytelling. Both Superstars are on the wrong side of 40, but are still in good shape and could put on a 15-20 minute match with ease.