We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
IMHO this is a terrible waste of money. It would be less so I think if they had simply glued together a trillion 1 euro bills into a huge tower to show off their wealth and wasteful thinking. A monument to self in a country with terribly poor people in need of simple necessities of life.
Been to Spain recently? Check it out in person. As for waste of money, at least it is not YOUR tax dollars and has been contributed by a lot of those "terribly poor people". And has funded, like the ancient cathedrals, a lot of middle class artisans. Think of it as a stimulus project, only not by government.
Then go stand in the middle of it and just breathe.
As Sagrada Familia is self-funded, it was the decision of those paying entrance fees to Sagrada Familia to "waste" their money. Judging by the visitor comments, not many of the visitors considered it a "waste" of their money. Many of the paying visitors to Sagrada Familia are foreign tourists, not "terribly poor" Spaniards.
GNI per capita, PPP (constant 2011 international $), 2015
United Kingdom 37,931
United States 53,245
Not that "terribly poor," apparently.
While I am not a churchgoer, my family background is Protestant. There probably hasn't been a Roman Catholic in my family tree for over 400 years. As such, I grew up accustomed to the austere setting of many Protestant churches. When I saw the Baroque settings of many Roman Catholic churches in Latin America, I found out I rather liked them. Sitting in such settings was of itself a religious experience.
I get the impression that similarly, being inside Sagrada Familia can of itself be a religious experience.