Review on 🎮 40 Pcs Colorful Silicone Thumb Stick Grips Cap Cover Replacement, Analog Controller Thumb Grip Cap Cover Accessories for PS2, PS3, PS4, Xbox 360, Xbox One Controller by Chris Pettway

I bought a couple of cases like this a few years ago and just needed to replace them. They expand the PS4 controller's thumb space and offer much better grip and control than the standard PS4 controller covers. You don't even have to buy these special covers, maybe try a pack of several types and try them out. Any joystick cover is probably better than a standard PS4 joystick.