A keyboard is a 100% digital instrument with many options and functions. In fact, it is a DAW, with ready-made keys and knobs. So you practically don't need a computer. In appearance, a keyboard only has the keys that are comparable to a piano. If you look further, there is no similarity whatsoever. But they have ensured that it can also produce a piano sound and digital amplification, etc., etc. For people that is a reason to buy one. Just like in a DAW, one can use or not use the hundreds of digital functions. So also a step editor. Not because it has to be done, but because it is possible for a specific application. Of course, each user decides this for themselves.