The d-pad uses tactile buttons like the actual joycons with a membrane on top of it. Combine this with the poorly designed pivot spike in the middle that only adds to the stiffness, diagonal inputs become stupidly hard to pull off as you need to press down in both directions with enough force to push down the membrane and tactile circuit.

https://www.amazon.com/Controller-Compatible-Adjustable-Replacement-Ergonomic/dp/B08QJ3HXZT