Chaosmancer
Legend
It's not big.
It's big and muscular.
Orcs and Goliaths are noted for their extreme non-agility-limited strength.
Actually no where I have ever read in a fantasy novel or story have the ever claimed that orcs are noted for their non-agility-limited strength.
In fact, the strong but limited by their agility like all strong things.... is a far more common theme.
And let's pull back for a second. Orcs have NEVER in 5e had athletics, or any advantage to jumping, climbing or swimming. Not once.
And you already agreed once that Goliaths should lift more than orcs, so orcs losing powerful build makes sense. It fits with allowing Goliaths to be the best lifters, and it opened enough power budget to let them have a far more interesting and powerful ability.
Sure, Goliath's used to get athletics as part of Powerful Build. It was more important to the designers to emphasize their ability to rip free from grapples than it was to emphasize any climbing, swimming or jumping. They are still good at those things, especially if you choose to give them a high strength, but it wasn't emphasized.