AnkiDroid is trying to match the desktop version as much as possible, when it makes sense to do so.
More features means more potential bugs, more maintenance for the devs, and more confusion for the users.
In any case, vertically center aligning is just a bad option for flashcards. Don’t you find it annoying that the words keep moving and you can’t quickly find the beginning of the answer?
If a user really wants that inconvenience, they can edit the styling like I shared in your other post.