Theoretically, anyone who practices Ripple enough will gain Hermit Purple, and Hermit Purple is able to see things the eyes can't. Tonpetty was a stand user, not proof he's the best. But none the less, Lisa Lisa was an incredible Ripple practitioner, but Tonpetty was doing it all his life and teaching others to do it. And mastering Ripple in the Himalayan mountains is far harder and far more profitable than doing it at ocean-level. Tonpetty got Hermit Purple for a reason.