There are areas where the bureaucratic hurdles to changing anything and the incentives for changing anything work out to nothing ever changing. I assume in 20 years most of Berlin is still going to have 50mbit/s max. I hear residents of New York have completely given up and are using 5G modems because putting up new cables just isn't practical. On the other hand, these cities do have a significant minority of flats with gigabit internet, so if you care you can pick a modern building with modern cabling. Maybe the segment who both live in old apartments and also are willing to pay for fast internet is too small to bother with.