Even if I were to concede this point, it's certainly not honed by the kind of exercise that OP is advertising. We are deep in Max Howell's "invert a binary tree" territory here.
Invert a binary tree is kind of a strawman for the absolutist claim that you don't improve the cleverness by practice, but it's an example that not all the practice is useful
Only up to the pretty low point. After that, it becomes completely absolutely useless. And people collectively spent astonishing amounts of time training that for job interviews long after the "absolutely useless" bar was passed.