I type fast enough that somewhat longer names don't hurt. Also tab completion has existed both in IDEs and in shells for many years now. But just like very nearly everyone else I fall into the "7 ± 2 items in working memory at once" capability range. Having to remember what a command/function/syntax element does instead of reading a word that says what it does takes away from that working memory.

Long-term memory is similar, while it's not bounded in the same way it takes time and effort to develop. I'd rather type `git new-branch` than have to remember `git checkout -b` and I certainly don't alias it to `git nb` or something: I can type `git n<TAB>` and let that complete it.