

This is not necessarily the case - it has been shown that slower car speeds in cities leads to better traffic flows and thus can lead to more efficiency of car travel, less traffic jams. So everyone driving slower can lead to more reliability and less average travel duration of cars.
In Berlin, only 3% of all registered cars are pure electric cars (numbers from 2024).
Speeds of 30 km/h lower the emissions of nitrogen oxide from cars with combustion engines. This happens because of significant reduction of pollutant-laden acceleration processes.
The reduction of emissions from such a speed limit is based on more uniform traffic flows.