It seems bad form to declare something is dead when you didn't work on it directly, and other people clearly are working on it as evidenced by the latest versio

It seems bad form to declare something is dead when you didn't work on it directly, and other people clearly are working on it as evidenced by the latest version of the spec being less than two months old. I don't know whether WebUSB is healthy or not -- but the OP clearly doesn't either.