To put the Germany thing in perspective ...
Yes you can blast along at 150+ on much of the motorway network.
There are restricted sections though.. either side of intersections for example.
So if there's a limit, there's a reason and from what i've seen, it's mostly obeyed.
BUT, you can also be booked for speeding @ less than 20mph !!
Outside schools for example. Happened to 2 of my relatives.
So, where a limit is merited, it's there... and enforced.
Seems perfectly logical to me... but then common sense often does.
If there's no real need, why artificially (and needlessly) jam up the traffic....
at some arbitrary speed ramdomly plucked out of the air in the 1960's.
Drivers can concentrate on driving rather then looking for cops + cameras.
It's all irrelevant anyway. The flow of traffic now on m/ways is way over 70.
If they make the limit 80, anyone obeying it will still be causing an obstruction ...