Yet I'm also talking from experience from both using a capacitive phone and being a physicist.
You don't seem to understand what is causing your percieved increase in accuracy but it's not the shape of your nails pointy or otherwise. It's the pointy flesh so cut your nails into a pointy stylus, a flat, a shape of a unicorn, or remove your nail altogether it makes no difference as I said your nails are not doing anything other than providing the space preventing you from flating your flesh against the screen. For a much larger contact area than that required but all of which doesnt matter anyway because only a point will count a point which is harder to guess when you don't know the exact position under your flattened flesh. I will reiterate your nails are doing nothing,no matter their shape.