How much of that je ne sais quois can be attributed to the age of the building, the scale and the handcrafted nature? Will that feeling be lost if a 1:1 replica is created?
I wonder what the original designers and craftspeople would have thought? If they would be in favour of a facsimile or an entirely new reinvention using contemporary architectural ideas
Most of the effect must surely be attributed to the conscious choices explicitly designed to make you feel small and pious, right? Though I think for some people a fair bit of the experience comes from thinking it is very old and holy, so if you tell them it's a 1:1 replica they'd be disappointed.
Probably the original craftspeople would be hella jealous about reinforce concrete and insist on building some big towering monstrosity that doesn't respect the architecture around it. That was after all what they set out to build, a big hopping temple to god that puts everything around it to shame: give those guys a big budget and reinforced concrete and you have a new flight hazard in the middle of Paris.
Whenever a cathedral suffered fires or collapses, or simply when a section went out of fashion and they had plenty of spare money from trade, they would indeed rebuild entire sections in a contemporary updated style; so I think that answers your question.
I wonder what the original designers and craftspeople would have thought? If they would be in favour of a facsimile or an entirely new reinvention using contemporary architectural ideas