Right. United set up their game plan in the ideal ETH way. Clog the middle which allows a ton of room out wide but, if done well, limits the quality of the chances opponents have.
ETH knew that they had no hope of beating City if they had tried to go toe to toe with them so they had to set up that way. The players bought in and performed excellently.
And yet it wouldn't have really mattered unless City also played like trash. Alvarez missed a great opportunity, Haaland hit the woodwork, KdB had multiple passes to absolutely no one despite not having pressure on, etc. That gameplan also basically relies on scoring first. If your opponent scores first and you have to open up, it can turn very ugly, very fast.
Basically United set up perfectly and executed perfectly and, excluding the howler giveaway to Garnacho, still lost the xG battle 1.34 - .54 and would have drawn 1-1.
It was a good setup no doubt, and basically the only chance they had of winning, but I refuse to call a gameplan brilliant when it relies on the other team giving up a howler, missing chances, and overall not playing well.