Why not limit just fossil fuel vehicles then? That would encourage adoption of electric vehicles while keeping the freedom of the autobahn and reducing emissions just as much.
This happens to me regularly, and I'm not even living in Germany and driving on the Autobahn, I'm just living a little further to the East where the police is less rigorous in pursuing this type of traffic infractions. As long as you use the passing lane only when needed you're fine, nothing bad happens.
https://youtu.be/ys7HutH54No?t=111
Again, this is normal for the Autobahn. All the bad behaviors you see on US roads (left-lane hogging, passing on the right) will get you an expensive ticket there.
That's not something I'd necessarily be opposed to in the future, but we need to get WAY more electric cars into use first.