I think the reason World's has been so good, is the same reason so many people dislike Solo Queue
There are too many OP champions and games snowball too hard.
In past worlds, we still saw underdogs win a game or two over the favourites. In fact, it was rare to see a favourite win a series 3-0. However, the underdogs would win with either a niche champion pick/strategy or an OP pick and the favourite would respond by just banning out the practiced strategy and then winning any "normal" game.
Take RNG vs G2 for example. We all knew going in that G2 would try to win by split pushing. And they did just that. RNG couldn't just ban out the "OP Splitpushers" because there were too many of them. Aatrox, Urgot, Irelia, Akali, Fiora - how do you ban all 5, meanwhile when you need to ban Heimer as well?
Then take the jungle picks, how many AD dueling stat-check run-at-you-and-kill-you junglers are super strong right now? Nocturne, Xin Zhao, Lee Sin, Camille, Olaf. How do you ban them all?
And that's not even considering how broken LeBlanc seems to be in any game she sees play. Or that Kai'sa and Xayah are both big threats in the ADC role.
The "favourite" can't just ban out a strategy they don't want to deal with. Which is probably a good thing.
However, it's the same thing that's causing players to hate casual league.
I don't want to deal with a jungler that's able to 1v1 anyone starting at level 1 onwards, can clear fast, has gank pressure, etc... Aside from Lee Sin (who thankfully falls off) all of those picks basically do the same thing to you. It's almost a waste to ban one of them, because the player can just jump to another without really needing much practice - the skills are all basically the same. And yet, they're all among the strongest champions in the game.
I'm sure there's lots of other players that don't want to play into an overbearing top lane opponent, and yet again these split pushers are among the strongest champions in the game.
And then we get to the snowball point in the title. You give any of these champions a lead, and they can snowball it out of control. You can't stabilize a game and stall out to late. Yes, I don't want games to go 60+ min (even casual ones). I want to be able to sign into a game when I only have 60min available and be confident I can finish it. However, I don't want games decided at 20-25min. If coordinated pros can't stop the bleeding and prevent games from being wipes within 35min, how do you expect solo queue players to stop your feeding teammates from allowing a 20min stomp?
Just my view: Worlds is the best ever BUT It's the same thing that has made solo queue so frustrating.