That's known as the prosperity gospel, and it is not the same thing as the Protestant work ethic. It is also a particularly modern problem/belief, and unlikely

That's known as the prosperity gospel, and it is not the same thing as the Protestant work ethic. It is also a particularly modern problem/belief, and unlikely to be the cause of the economic differences between Catholics and Protestants. The Protestant work ethic is far more about the theology of the Reformers, and in particular the Calvinistic Reformers. Their doctrines included the idea of doing all that you do for the glory of God (including your vocation, and thus compelling excellence at work), treating your material possessions as ultimately belonging to God and not yourself, and thus not to be wasted in frivolities, denial of the self and self-pleasure, resulting in less waste on "fancy living", and much less of a focus on giving to the Church as a means of attaining grace. This resulted in private individuals accruing more wealth. It certainly isn't the only reason for European capitalism and wealth, but it appears to be a factor.