Do you have a computer telling you that speed or are you just making a guess? Because I find it unrealistic to be +30 kph on flat ground with a mountain bike for 30 minutes.
I say this because I have a gravel bike and can only keep +30kph for long periods if I'm on a slight incline and I'm pedaling with a purpose (not full sprint, but you wouldn't see a commuter pedal that hard)
On average people in commuting bikes will most likely be at around 15kph, low 20s on descents.
All regulation is written in blood. If there was no regulation, everyone would be cutting corners and we'd get daily titan submersible-like situations.
Do you want a piece of suspension up your ass because a cab driver hit a road bump too hard?
Do you want your legs amputated? Because we can make bumpers go lower and more pointy to improve fuel efficiency.
If manufacturers could, they'd drop the catalytic converter and we'd be back to seeing/breathing cars spewing thick black smoke.
All that and they would still charge you the same as now.