And I wouldn't group Catholicism with the mainline "less demanding" churches. A Catholic that truly lives the teachings of the Church is in the most demanding Church there is.
I’m not grouping Catholic and mainline on a personal whim, I’m reporting what the pew poll found in its research.
While it is true that almost all denominations are in decline, evangelicals declined as a percentage of overall population, but grew by about 2 million. Again, what the research said, not just personal opinion.