#4 Far too crowded a card
There are far too many matches in the SummerSlam card already. Sometimes, it becomes a chore to sit through a show that is far too long, which is why I'm glad that not everyone is in the card. Not only are the titles being defended, Trish Status and Goldberg are also coming back for showcase matches.
In fact, the cards are so stacked that the rumor is that there won't be a spot for either Tag Team Championship or the Intercontinental Championship at all. Personally, I'd want to see short and quick events, much like an NXT TakeOver is. Anything that drags on for too long loses you down the line.
There was just no spot for Braun Strowman in this card, I do suppose. Maybe he returns with a vengeance on the RAW after SummerSlam to bring chaos and dismay to whoever is the Universal Champion.