The Hypercarry Problem
Long and short of it they scale way too good. But they are supposed to but on the counter side of this they are supposed to have a very terrible early game and okay mid.
The problem arises that hypercarries are usually too safe and can't be punished enough early or the amount of gold they need for their items is not significantly more than mid game or early game champs or they comeback when they hit a certain level or item. A good example of the gold is the crit items these are the most synergistic items in the game and the average cost of 3 crit items that you would want is 8700 gold (items chosen were RFC, IE, and PD) while the other hand a bruiser with 1 damage item and 2 tank items would also cost 8700 (iterms choses were Spirit Visage or Adaptive Helm, Black Cleaver, and Deadman's Plate). Extra note: If you were to use a steraks gage and titanic hydra instead of armor and mr items the cost goes up to 9700. Even an on hit build using BorK, Rageblade, and crit item only costs 9000 gold.
The trade off is that the healthier items are supposed to be good by themselves and are a little more gold efficient by them selves as well as give some room for error but not as synergistic as crit, while crits trade of each component is slightly less gold efficient but their synergy makes them more and more gold efficient when paired with other items but are very risky to take. On hit is somewhat a healthier option with life steal in the build and better more reliable sustain. The problem comes with the synergies made specifically for hypercarries with runes and their kits giving them the cheaper and more gold efficient items allowing them to carry a game way too often allowing them to overtake anyone who isn't try to make a play against them to set them behind at the risk of them getting ahead.