Electric bikes

As anyone who's been watching delivery riders knows, e-bikes already are the new mopeds. They're easy to delimit and lots of people do it, as aggi says. This will continue to be a problem with these things (and with e-scooters), and enforcing lower speeds would require massive police resources that won't materialise. So, yes, the best route is probably to put them in the same regulatory bracket as mopeds, i.e. requiring a driving licence and all that.

As for 'gap in the market', ultimately it just comes down to practical factors like cost, durability, how far can they go on one charge, how comfortable are they, what kind of social cachet do they possess, etc. It doesn't have to be a clearly-defined gap in the market, just overlap or narrow slots will do, and of course it's entirely possible that e-bikes might eventually out-compete traditional mopeds if they were put on the same footing. They already seem to have out-competed them in London owing to the lack of regulation; it would be interesting to see what would happen were new regulations to come in. Both mopeds and crank-driven bicycles are, after all, bicycles, that is, 'two wheels, of which one is steerable, attached to a rigid frame'. As Mike Burrows says, in engineering terms the really significant innovation made by Karl Drais is that he found that you can stay upright on a narrow, single-track cycle through steering. All the other stuff, whether crank drive or any kind of engine is secondary to that in importance, but given that the basic concept is always the same, these secondary things will make the difference when people choose what model to buy.

Needless to say, I prefer the kind of bicycles on which I am the engine, but I'm not too worried about e-bikes as such, as they do have sensible applications, such as cargo e-bikes, e.g. as shown by Pedal Me. What really worries me is how many young people ride them. Sure, some of them may ride them much greater distances than they would on a non-engined bike, and some may 'replace' cars by e-bikes, or switch from public transport, but the evidence suggests that very few do that, and that most people merely become less active than they were before. This negates what up to now has been the single biggest benefit of cycling.

There's also the safety problem, although that is secondary to the loss of activity. Still, one of the first consequences of the increase in e-bike sales was a much higher crash rate in countries like the Netherlands and Germany. I was in Germany recently, and it really is a sight to behold how people who are evidently very bad cyclists run into problems through speeds they can't easily control on a two-wheeler. It's not as easy as it looks when people do it who have been cycling all of their lives.