Configure "Add to cart" button text as a display format setting

Motivation

As documented in #1147690: Make "Add to cart" button text a display format setting (configurable at the field level by content type), Commerce 1.x used to allow "Add to cart" button text in the add to cart field formatter to be configured.
As far as I can tell, tracing the commit history, this feature was not included when the formatter was ported to Commerce 2.x. It seems that after the initial basic port in b631e183 (8.x-2.0-alpha1), the feature was missed out and never reimplemented.

Should this be reimplemented in Commerce 3.x or was it intentionally excluded for a reason?