We live in a house from 1900 and thanks to a lot of work our apartment has the energy efficiency grade A to B. We will also get a heat pump in the next few years. We have PV on the roof (I’m not sure what for right now), our windows are triple glassed and we have two heat exchangers thingy that sucks air from the outside and pushes inside air out. A couple of months ago they also insulated the roof of the basement better.
We are very lucky that the owner is behind all these works. Most aren’t, but it is to show that you’re absolutely right and how much can be done and improved. (However, I still don’t like the cut of the apartment or not having an elevator/barrier free access to the basement. And the bugs.)