The function of a thing can be solely "wow, this thing is impressive", and that's fine.
Even if medieval churches had no purpose other than to construct an impressive structure, that isn't something we ought to deem unworthy. Greatness is a fine goal in its own right.
After all, art museums and concert halls overwhelmingly display the things that people find impressive. The things that people don't find impressive don't stand the test of time.
Utilitarian function is certainly a great virtue, but it is not the only virtue.
Even if medieval churches had no purpose other than to construct an impressive structure, that isn't something we ought to deem unworthy. Greatness is a fine goal in its own right.
After all, art museums and concert halls overwhelmingly display the things that people find impressive. The things that people don't find impressive don't stand the test of time.
Utilitarian function is certainly a great virtue, but it is not the only virtue.