It sounds like you're describing a 2-stroke engine, which older Vespas did use. But modern ones use a 4-stroke engine and should have the same emissions profile as any other motorcycle.
I live next to a road and combustion-engine mopeds vary from "holy fuck this is loud" to "I can't wait to move out". I used to live close to an airport and that was much better. The specific noise that mopeds make drills into your head. Funnily, I'm never bothered by nails on chalkboard or cutlery on plate, but mopeds, holy fuck, if hell exists, it's full of mopeds.
I own a Piaggio 300cc Scooter, not called a Vespa because it is one of the big wheel variants (similar to Honda SH line) but it has the same engine as the Vespa 300GTS.
It is not at all noisy unless I rev it high, which I try to avoid doing most of the time. It is not loud like for instance a Yamaha T-Max, not helped by it attracting mostly complete retards.
Obviously there are always dumb people mounting akrapovic or other noisy aftermarket exhausts on any bike brand but it is also the same with cars.
For better or worse, probably worse, the definitions of both "moped" and "scooter" vary from person to person or jurisdiction to jurisdiction. "Moped" is often used to describe a light motorcycle.
Ive been riding scooters and motorcycles for 20 years and I to this day I have no clear image of what a moped might be. I always imagined a theoretical spectrum from pure bicycle -> gas motor equipped bicycle-> moped -> pure motorcycle, but have never encountered a moped.
I'm not disagreeing with the origin of the word, I'm just saying it's expanded and changed.
Have you ever "shipped" something that at no point in its journey was carried on a floating vessel? Do you correct people when they say they're shipping something by ground or air?
I’m a big advocate of two wheeled transportation. The differences between bicycles, e-bikes, mopeds, and motorcycles are important and meaningful. The misuse of terminology by entitled car drivers and the ignorant public literally kills people every day. Yes, I am aware people are wrong. No, I don’t care to compromise.
I haven't been following the latest developments but about 10 years ago they launched "Vespa elettrica". It was very expensive and low powered at launch. Not sure if they've iterated on it since.
I suspect that other brands of electric motorbike may be better