The assumption that a set maximum speed is the safest for all drivers is erroneous. There are many factors at play and a proper safe speed depends in part on the driver, the driving conditions, and the car they are driving (and much more).
Unless you are in very heavy traffic, forcing people to go slow or worse to pass you on the right is causing a much larger safety issue.
If we are interested in improving safety imo we should be focused on things like vastly improving driver education and requiring any driver to show knowledge, understanding and skills related to driving - including and especially on high speed highways. In California, you can get a license without ever actually driving on a highway (or "freeway") - which is absurd.
Please compare death rates from countries around the world (including Germany): https://en.wikipedia.org/wiki/Autobahn#Safety:_international...
It's much harder to get a license in Germany than it is here in the US!
The motorway death rate in Germany is almost half what it is in the US.
I urge you to think about this and question your assumptions.