There it is in some places it's just to restrictive but on the other hand there is a point when it's not bicycle anymore and should be treated as such. Emb network just did a thing about this. The numbers here in the states are pretty good thou I like to see just a tiny bit higher but can't honesty justify much higher before it should be considered something else.
Given the vast expanse of Australia those limits make no sense at all. I think gas powered bicycles
should also be legal to at least 20 mph,(under 50cc). By comparison their mileage is much better
than cars & initial carbon footptint far less. This would also make sense in the US since it might
bolster our dead travel & tourism industry with minimal eco-impact & the traveller with more to
spend. Interstates at 70 mph are not really a fun way to get around. Not need to go so far if one
can enjoy pleasant paths & back roads. Distance here are still limited by current ebike range.
I have built a hybrid gas/electric bike with a range that greatly exceeds 200 mpg.