What? This is really dumb. Museums are extremely practical, just like schools: they educate people. Concert halls are for entertainment; they're just as useful as restaurants (after all, you could just eat microwave meals at home). Most public buildings have some kind of valid use that doesn't involve superstitious beliefs. Even medieval churches probably had some non-supernatural uses, I'm guessing, like being used as meeting halls or for public addresses. Egyptian pyramids had none of this: a few pharoahs' dead bodies were sealed away inside them along with lots of treasure, and that was it. Everyone else got dumped in a pit when they died.
Edit: I see your point now, that medieval churches had other functions besides the religious stuff. Still, I see those things as only secondary functions to the buildings; museums and concert halls have those things as their primary functions and are optimized for them. I've been in medieval churches, and there's very little artwork in them, relative to their size, compared to any decent art museum. But I agree, they were a lot more functional for the people of the time than the pyramids.
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.
Pyramids were likely symbols of power and unity[1], for the pharaoh of course, but also for the whole Egyptian civilization. This is a very practical purpose.
[1] In fact the burial aspect might even have been a secondary one.
Edit: I see your point now, that medieval churches had other functions besides the religious stuff. Still, I see those things as only secondary functions to the buildings; museums and concert halls have those things as their primary functions and are optimized for them. I've been in medieval churches, and there's very little artwork in them, relative to their size, compared to any decent art museum. But I agree, they were a lot more functional for the people of the time than the pyramids.