Suspension of disbelief.
Previous entries in the franchise at least made the attempt to keep things believable and within the realm of possibility. Wick was not merely successful because he was wearing plot armor but because he really was just that good. The gun fights and hand to hand combat had an air of plausibility, this started to wane in Chapter 3 but i digress. The adversaries Wick faced presented difficulties for him and he almost died a few times. The perceived realism in the fighting was the main reason i liked the other films.
In chapter 4, the enemies John Wick faces are far too numerous and blatantly incompetent. They are clearly just cannon fodder fed up to him to massacre for the entertainment of the audience. The film even makes a joke of itself by making outright John invincible to any damage. Truly an insult to the other films and to the fans. So many things ruin my suspension of disbelief not least of which making Donnie Yen’s character blind(why?).