Because the Uso's started copying them and doing a mediocre job of it. Uso's have improved their overall package as a heel unit, but when it comes all the way down to it, have not had a memorable match in their careers. Plenty of good ones, nothing that special. Not even a few years back when the tag division was really hot following Cody and Goldust first teaming.
We're comparing arguably the best overall act on the independent circuit to not even the best tag team in the WWE.
The REAL question is are the Bucks better than The Revival?
Usos had good to great matches with the SHIELD, the Wyatts and the New Day. They were practically the one constant in the tag division over the years, I think they are solid.