When it comes to controllers, each of the big 3 have their own philosophy. Nintendo radically changes their controllers each system, going from an tri-handle shape of the N64, to a dual handle and weird button layout of the GameCube, then a remote, a giant tablet, and now currently on detachable gum-sticks. Microsoft sticks to tradition, barely adding to or changing the functionality of the Xbox Controller since its introduction. Sony however, has always been a happy medium between Microsoft and Nintendo. Innovating on input methods, while not tampering with the core design and layout. Even the DualShock 4, the first major redesign of the controller, still fundamentally feels like a controller from the late 90s. Each DualShock has added something new with each PlayStation console. The DualShock 2 for the PS2 introduced pressure sensitive face-buttons, the DualShock 3 introduced Sixaxis motion controls, and the DualShock 4 introduced a touchpad.
Keeping with the formula, what new input or feature could Sony introduce in the DualShock 5? I think the DS5 could implement a Switch-like HD Rumble feature, which would help with VR, but I struggle to think what other inputs could be added. The DS4 is already one of the most fully featured controllers on the market, so unless it's something we've never seen before, I don't know what else could be added.