It does happen occasionally, but DB tends to run, maintain and sometimes upgrade its successful (~reliable and widely introduced) rolling stock until it falls apart or is grossly outdated (40+ years old). Rail passenger numbers are increasing, so there is no need to sell stuff to downsize.

The Flixtrain company uses 40+ years old IC (intercity) cars - they have no air conditioning and it's really loud inside with open windows, especially so in tunnels. That is the kind of stuff that DB sells.

Hrrm. Funny. I thought that those were so called "Eurofima", which I remember as fucking cold in summer, because then their AC were set at full blast, which was annoying at the times.

https://en.wikipedia.org/wiki/Eurofima_coach

Also no real opening of windows anymore, because early onset of https://de.wikipedia.org/wiki/Druckertüchtigte_Schienenfahrz... <- meaning pressure protection against passing trains at high speeds, entering tunnels, and such.