Why is focus deprecated on HTMLSelectElement?

Question

According to MDN HTMLSelectElement reference, focus and blur methods are being deprecated since HTML5. Why is this?

Answer 1

The focus and blur methods have been moved to the HTMLElement interface from which the HTMLSelectElement interface derives.

This makes sense, since any element that has a tabindex attribute can gain and lose focus, not just specialised elements as may have been the case when DOM Level 2 HTML was written.