I live in a 50 year old house and there are a lot of things we wouldn't do today. The walls are not well insulated and hard to retrofit. The attic meets minimum standards only because I added extra myself a couple years back - I wanted to do more than the minimum but the way it is built there isn't room for more. At least I avoided aluminum wiring (which was common a couple years before this house was built) but there is a lot about the wiring that doesn't meet todays standards. It isn't just style that we layout houses differently today. This house has been remodeled at great expense (30 years ago) and there are some things that are still wrong.
Which is to say tearing down and building new to the latest standards is a good thing.
I live in a house that was built in 1840, and none of the issues you're complaining about exists here, since I had everything refurbished when I bought it.
Destroying an entire building to fix the wiring or insulation would be insanely wasteful.
Concrete is one of the most CO2 emissive technology, and it also consumes way more sand than what natural erosion produces, and thinking that all of this will be rotten in a century is heartbreaking.
I also refurbished my 50 year old apartment which is part of a cute concrete monster i wouldn't change for the world. I've had no issues doing this and attained the highest possible energy rating because the architect that designed the building was a genius.
If they are 50 years old, they are already, it may be hidden but the concrete cancer has most definitely kicked in at that point. Don't worry it's not going to have dramatic structural impact for the next 50 years, but at some point the bill will start coming to try and keep the building from falling apart. Until it's not economical to do so…
