There is some truth to your point (although Catholics do not make it when counting the number of believers in different denominations worldwide. But if you look at the US map of most popular
denominations by county you will find that blue states are generally Catholic. Church attendence is also lower in predominately Catholic states. That suggests that Catholics as a group are less devout.
Secondly, evangelicals are converting Catholics both in the US and abroad.
There is some truth to your point (although Catholics do not make it when counting the number of believers in different denominations worldwide. But if you look at the US map of most popular denominations by county you will find that blue states are generally Catholic. Church attendence is also lower in predominately Catholic states. That suggests that Catholics as a group are less devout. OR it suggests that many people who don't really have a faith still refer to themselves as Catholic. Further, using your approach looking at county maps, Mormons are the best Christians.
Secondly, evangelicals are converting Catholics both in the US and abroad.
And Catholics are busy converting non-Christians.