I dont think itd be much better but it has a small footprint and is more usable at that size than a trackpad. I think those are good qualities to have for a small portable device like this. I like my steam deck but I dont personally use the trackpads often and almost never the one on the left so one small nipple would be amazing for me. I used it a lot on my old lenovos.

The little square below the joystick is a touchpad apparently. I think it wouldbe cooler though if they just used the nipple from their laptops. It would be smaller and IMO more usable than such a small touchpad.