Like any instrument (and as others have already said) you need something to practice on. Even a cheaper keyboard that doesn't feel the same as a Piano is better than nothing. I started out on a pretty cheap set of drums with pretty low quality hardware for example. Eventually I reached the point where things like my bass drum pedal being low quality were holding me back, but I still learned a lot and developed a lot of valuable techniques and abilities on that kit, even if it wasn't the same as playing on a kit that cost thousands, and where every piece of hardware is made so you can play your best.

Everybody has to start somewhere, and personally I think getting along with cheaper gear at first is a better idea than buying a fairly expensive keyboard or piano out of the gate. You'll appreciate the good stuff more when you eventually buy it, and if you don't stick with it, you aren't out too much money.