That might have been the case 30 years ago but now that vehicles are transitioning from ICE to EV the validity of claims that restricting cars and decreasing speed limits will improve air quality and decrease emissions is steadily dropping...
We are currently at 4% electric cars in Germany, so no it still make sense to have a sane maximum speed limit. I actively hate driving from Lindau to Munich, because the road is full of (mostly swiss) €€€ sports cars driving like crazy, because it is the only road the can legally drive fast with their cars. Please give us the tempo limit!!
Yes but people correctly understand that once a speed limit is imposed, it will never be revoked, even once Germany is 90% electric. That's the nature of regulation.