Back when the Puritans were around and trying to purify the awful Church of England, one of the things they loved was nice, simple, plain churches. This is a common desire still among many Protestant denominations, especially newer ones. Some Protestants look at the gorgeous cathedrals of yesteryear and wonder, What was the point?
I've mentioned before how a lot of how Catholicism works can be easily explained by picturing life and minds of people during the Middle Ages. I think that works again here.
And why did the building have to be so extravagant? In our modern world with developed minds we don't really see it this way, but medieval Christians felt that they were bringing glory to God with their creations. Their actions benefited themselves of course, because obviously God can do without lavishness if need be, but it was an exercise in helping the person to bring God the best, just like the Jews would sacrifice the best animal they could afford. It's another instance of "fake it 'til you make it" in Catholicism--actively working for God and in turn gaining greater devotion to Him.
But what place does all that have now? I think it's still relevant. Maybe we don't need all of our newer churches to be built the same way, though I do think the pictures and storytelling can still be beneficial. But even today, we still have these cathedrals of yore. And I've visited a lot of them. During our travels we must have visited at least 30 churches, and most of them were magnificent buildings. I always considered the men who labored to build the church. Many buildings took hundreds of years to build and generations labored one after the other. These poor people never even saw the completed building.
To me, these old churches are not obsolete in our modern day. They continue to serve their purpose by teaching and reminding me in a very physical and tangible way of a faith that can sometimes be hard to grasp. A blog post I read earlier this week reminded me that this was a topic I wanted to touch on and I encourage you to go and read it here.