The don't need or have disc brakes in the Tour de France at over 5 times 12mph downhill.

I ride both types, a non-assisted Cube and a Kalkhoff Pro-Connect. I use both to commute along the same route which is a mixture of towns, rural 40 MPH A roads and country lanes. The type of bike you are riding makes absolutely no difference to safety. Safety comes from the bike rider. It's no one else's responsibility and it's certainly not anything to do with the legislators who imposed the 15 MPH max assist speed.

 

The bike rider has to take account of the constantly varying situation and part of the picture is the type of bike being ridden. The best safety mechanism is an ability to be self critical, to know when you have done something stupid, admit it to yourself, learn from it and don't do it again. There is always a danger of being wiped out by the reckless actions of someone else, even if you are totally in the right, but with good vigilance and good a perception ability (nurtured through self analysis), the probability of that happening is lowered. We, the cyclists, are our own biggest danger. We must take on the responsibility of mitigating the consequences of actions taken by fools. Morally this isn't right, but that's of no comfort when you have been squashed.

I think this post pretty much hits the nail on the head.

The only thing I would add is that in my opinion proper bike maintenance plays a far greater part than whether it be electric or unassisted.

I see far to many bikes in daily use with cracked or badly worn tyres, badly adjusted brakes and worn out brake shoes, loose steering, gears which don't engage properly causing the chain to slip suddenly, mudguards hanging loose which could slip into spokes, etc. A lot of these sadly being children's bikes where the parents seem to think that making them wear a helmet is all they need to do.

Maybe there should be an MOT for bikes but I don't know how it could be worked.