What makes monuments like Notre Dame or the pyramids special is that they DO imbue this sense of continuity. Everything else in our lives comes and goes, but a few things we as a society come together collectively to say "This is special and worth preserving." There is a special feeling of connection one gets from that sense of unity across time. These are the things that give us a sense of shared history and a shared future destiny. And it has the effect of simultaneously making you feel individually small and insignificant, but also important and part of something grand.
The first time I visited Paris I remember one of my most dominant thoughts was that nothing like this will ever be built again. There is so much in the art and architecture that, by modern standards, would be deemed wasteful and extravagant and a suboptimal use of resources. We don't value aesthetics in the same way. So when these things go, they're gone forever. Even if remade they will only ever be an imitation of a way of thinking and a way of life that has gone extinct.
They won't even serve to remind us of those old ways because the gestalt you get from layering generations of use and the peculiar artifacts of the material culture that created it will be gone. That's why people mourn. It's not just about the building, but the fact that the building anchors them to a sense of tradition and continuity.
And it's not the first time these things happened. It was mentioned that before it was a Christian church it was a temple to Jupiter in that location. Removing the old pagan monuments was a conscious effort to FORCE just such a break from the past. To say the old pagan ways are over and to sever any sense of continuity with that old culture and their old Gods. I'm sure it was just as troubling or traumatic then too.
We still have some collected myths and stories from the Romans and the Norse and so on, but a lot of these were written by Christian converts who were sad that the stories they heard on their grandparents' knees were going to disappear. They may have converted, but they felt like this was something important that needed to be preserved.
We have Roman myths as written down by pagans pre-Christianity.
But our records of Norse myths were written down around 1200 AD, a couple of centuries after Christianity became the official religion in Scandinavia in 1000 AD. It is hard to say how much modification there was between those points.
The biggest change is that Odin/Wotan finished his long journey from being recognizably Mercury when the Romans met the Germanic people to absorbing a lot of the character of Tyr (aka Mars) and then becoming king of the gods. The historical root survives in language, Wednesday is still named after Wotan in English, and after Mercury in various Romance languages.
There is reason to believe that during Viking times, Thor was (like his analogs Jupiter and Zeus before) still the king of the gods. And therefore Odin's role as patron of kings and poets both was responsible for his elevation in the version of the myths that got written down.
Out of curiosity, what are the arguments that Thor was considered the highest of Gods originally? IIRC many of the ceremonial items they found on the boats were dedicated to Odin weren't they? (Though I suppose that being an analog to Mercury, he would make a lot of sense for voyagers to adopt as a patron).
Historical accounts such as Adam of Bremen describing Thor as the main god at Uppsala, the frequency of Thor's Hammer versus other religious symbols, the many references to Thor in Icelandic sagas.
However Tacitus did describe Mercury at the chief Germanic god. So maybe Odin was the chief god after all.
The popularity of Odin could also be a reflection of their social roles. Consider the Lay of Harbard: https://thenorsegods.com/the-lay-of-harbard/. Elsewhere in the myths, Odin gives Harbard as one of his names, and it is believed that Harbard in this lay is actually Odin. Reading that, you'll see why the average peasant would be more interested in asking for Thor's help than Odin's. Conversely you'll see how a war leader would be more interested in Odin's help than Thor's.
Get tickets well in advance.
Buildings now show incredible material science, technological development; but rarely the decades of learning of human craft directly applied to materials.
I think if we were going from rough-hewn to well-faced stonework, opaque windows or simple slits to translucent radiant glasswork, from flat ceilings to intricate vaulting, etc.. that we too would make that leap.
We are so much richer, we can afford to keep old stuff, hoard it even, and still have resources a'plenty to keep warm, feed everyone, and build glorious buildings.