My 2021 ran a 6.5/6.6 60 on natural talent alone. We sent him to a very well respected speed/agility trainer last year for some technique help when we realized what an asset his speed was. That trainer's first response was "yeah, he's fast, but he can be faster." He teaches a combination of specific strength training exercises and techniques to improve speed. So as others here have said, a player can definitely improve their speed to some extent. But keep in mind, natural speed is a result of physical attributes (check out the Sports Gene by David Epstein for more info). So there is a limit as to how much increase there can be.