There is an issue with people, especially teens, going like 40 on a MUP, but that's an issue of infrastructure and traffic enforcement any way you cut it.
Mopeds have been similarly easy to de-limit for decades though and nobody has complained. You crimp an offshooting sidepipe on the exhaust and that's that, proper jobs cut and weld it but crimping works just as well. 16 year olds in the UK are allowed to ride these things on everything except motorways and they go 40-45ish delimited depending on hills etc.
This complaint isn't safety it's absolutely just about opposition to electric.
Some of them are even more simple, like removing a washer from the gear assembly. Just unscrew the cover and take out a washer.
I agree you wouldn't want to share with them either, they're the same speed as all regular traffic. The point is that it's not about the safety because they've never given a shit about that, they're petrol based. It's about electric.
I know many of those, like the original surron, but they look like motorcycles and scooters, not bicycles. It's not impossible to make normal ebike-looking components go at that speed, but it will severely limit their lifespan or outright destroy them and you're still going to need an expensive large battery to make it work, so I'd be surprised.
There's the Bafang Ultra motor that can be hacked to do that (using a laptop and a special cable and shady exes from forums) but last I checked it will overheat and destroy itself without physically opening it and tweaking the thermals if you push it to those numbers. It's not easy to make a motor that can go at that speed and put out that much power and still fit in a normal bike frame.
It's already legislated to be illegal. The fact that it doesn't look like a bike means it's easy for the law to be enforced - if it doesn't have plates and looks like a bike and certainly if it's going fast that's easy enforcement. All that's missing is the pressure to get useless cops to do their jobs, but that's a solvable problem.