Yep, but (a) that isn’t portable Markdown, (b) your editor probably doesn’t support opening the link from the link text in that case, and (c) whenever you want to modify the link text you have to modify all occurrences. A word processor can handle that automatically for you. It can also offer completion (like tab completion) for references that you use repeatedly. It can show as a tooltip what a given link text links to. Conveniences like that is what computers are for, let’s not relapse to the stone age here.