Is EG the best choice just because they won champions? Or are you defining consistency with EG?
Measuring consistency (to me) is how likely I am of making the right predictions with that team. Luck is everywhere in both the game and pro scene. From random headshot through smokes and timings, to whoever is sleeping in and bracket draws, but top tier teams will minimize or exploit each part of the game's RNG, leading to consistent performances. There was the 2016 NBA Finals, where the Warriors were the favorites and lost a 3-1 lead to the Cavaliers, does that discredit what they did the whole year?
Hearing about EG's story and how they NEEDED MIBR (who were one of the lowest performing teams in that league), I wouldn't have thought that they were going to make it to champs in the first place. They have never beaten FNC, earning second place in Tokyo, and are tied with FNC in terms of series against LOUD (both 2-1).
Consistency is how top tier teams beat other top tier teams. There is a one in a million chance that a team like EG loses to a random team that gets 40 running headshot kills through a smoke, and make all the right reads, but that shouldn't discredit what they do would work the other 99% of the time.