I dont think you understand. There will be no supply chains to make these advanced materials. If we aren't doing it right now, it won't be here when the climate collapses. There will be no bug farm paste manufactorums. There will be no steel mills. You can't have skyscrapers when there are no supply chains producing steel to support the buildings, plus all the machinery to actually piece together the building. Construction will immediately be shot back to the dark ages or prior. Because it too relies on advanced global supply chains to acquire the materials to make the advanced materials to construct infastructure with.

I should also note we are on the hypothetical of complete collapse. We are already arguing in that context, I'm not actually waiting around like its a fact. But the billionaires are, they're building their bunkers expecting to make it (?) to some unknown date where the surface world is magically habitable again.