What happens if everyone moves to electric cars and the pollution problem from car exhaust disappears or is greatly abated in the inner city? Does closing the street off still make sense?
Specifically regarding Friedrichstraße: It's in the city center, brimming with tourists. 3 major subway lines have stops there. Few cars drive in there as it is, because you have bigger streets nearby that are better connections. If you still want to go with your car, you just park in a parallell side street, there are even parking garages if you don't want to look for a spot.
Having it car free will be lovely for the tourists, cafés and restaurants will put out tables.
The same was done in other city centers like Budapest or Vienna decades ago, and it worked out extremely well for everyone involved.
Rolling at speed means two surfaces are ground together which will produce tiny particles of stuff that get stuck in your lungs. Which causes a statistically detectable increase in breathing problems, thus a small bump in deaths.
Getting rid of motor traffic in city centres mitigates this problem, regardless of whether the cars are ICE or electric. We can't make it go away altogether because rolling fast is very useful - the public transport will be doing it too, but we can significantly reduce it.
Generations of racism have had a huge, huge affect on American society and the design of American cities.