For a fit person, no needs to purchase an ebike.
My son goes quicker on his travel bike as I can go with an ebike.
But, as I said in another thread, it is NO surprise that ebike is becoming so popular.
The fact is, that at least in Europe, they are the modern version of all the moped 45 km/h we all have known and used (Peugeot 103, Motobecane, Piaggio, Vespa, ...)., or Velosolex 25 km/h
The young people or people not in a hurry, commuters, ......doesn't have that anymore, they have Ebike.
I can not speak for USA, but at least in Europe it has always be very very common to use such moped / Velosolex daily, and this is exactly what an Ebike offers, in the same speed range.
You can carry everything , go easily into the city, carry the kids on a trailer, ....
I don't care if a guy with a road bike overtake me at 50 km/h. We are not doing the same thing, with the same goal.
Ebike is the future of bicycle, for sure.