Arrow keys should work like WASD keys for subtitle navigation

I remember that in a past build of the Language Learning With Netflix app, before it was bundled into Language Reactor, the arrow keys mirrored the functionality of the WASD keys:

Up arrow - paused/resumed video
Down arrow - replayed current line of dialogue
Left arrow - jumped to previous line of dialogue
Right arrow - jumped to next line of dialogue

Then that functionality went away at some point and only exists now on the WASD.

I feel like having both sets of keys mapped not only lead to more accessibility to those with different device setups, or disabilities, but also just generally lead to more comfort and ease of use as one can switch hands more easily and not build up repetitive strain.

Is there a reason why it was removed, or was it just something that slipped through the cracks?