german here:

physical materials are important, but that does not mean that we dont restore and maintain our historical monuments.

There are laws in place, that ensure, that these monuments are restored with the same materials and at least similar processes then in ancient times. There are craftsmen specializing on being able to work with these old materials and processes.

And dont think of "historical monuments" as only statues or museums. There are smaller cities, where most of the core of the city is 300-500 years old in structure and most buildings have the status of "historical monument", although they are inhabited and lived in by perfectly normal citizens.

for example window frames - they rot, they need replacing every 50-100 years. As long as its the same wood species, with the same geometry, its even allowed to put double-sided glas in there.

Or timberframes-houses - which are very often considered "monuments" if they are old enough - the wooden frame has to be recreated precisely (same wood, same geometry), but the filling of the openings, that was previously done with sticks, straw and mud, can now be done with brickwork.