Saying "Oh, canvas tag. Been there, done that" doesn't do this project justice. It is not new ideas that matter here. It is the execution of them into workable solutions.
People have been there, done that and been sued for it. This is an ADA Title 2 minefield, not a workable solution. They haven't solved that issue, so it remains a nonviable approach that will not make it to mainstream adoption just like the decade of previous examples.