Part of that is like the old and tired argument about guns. The thing itself doesn’t become a threat until handled with poor judgement and/or malicious intent.
And for cars we’re all used to share the road with other similarly sized cars that can have 2-3 times as much HP. And again, that capacity for mayhem and chaos usually doesn’t cause a problem until combined with poor judgement and/or malicious intent.
So it’s no way guaranteed that seriously overpowered ebikes have to become a significant problem.
But yeah, I understand your concern.
It seems to be a surprisingly widespread notion that electric propulsion and calling something a ”bicycle” somehow makes it ”safe” to faff about any old how. Ignore legal classifications, ride anything, anywhere etc etc. However, AFAIK, this casual attitude hasn’t as yet caused any serious accidents.