The Catholic church is not a measure of holiness either.
Individual Catholics, even some priests are far from holy. The Catholic Church is holy because she teaches Christ, Who is Holy, and seeks the company of saints who are holy. That is the difference: the Church is holy in her objective and her moral core; prosperity of the modern age does not have such intrinsic holiness ans moreover, Christ taught what a great danger prosperity is to a human spirit. "It is more difficult for a camel to pass through a needle's eye than for a rich man to enter heaven".