iPad 4th gen was just made obsolete by Apple and it was a much better device than the 3rd gen so I'd say it really isn't cost effective to replace the screen since it's not worth much.. Recycle it, you can turn it in to Apple at no cost
I think Apple would agree. In fact, I think they agreed the year it came out, because it was only a thing for about 9 months. Probably the worst iPad I ever owned too--ran really hot and was not keeping up with that retina display very well.