Humanlike intelligence is an evolutionary singularity: A development that fundamentally changes the rules of the game.

While our large, complex brains are a massive resource hog, it is highly unlikely that we will ever adapt in a way that robs us of our sapience simply because there will never be a time when sapience stops being beneficial.

A bird might lose its ability to fly if all of its predators live above the treeline and all its prey live below the ground, but a human with proper motivation can build a shovel to dig up prey and a sling/bow/blowgun to kill or drive off flying predators.