Where I see e bikes becoming more popular is in tourist areas with hills. Take a city like Galena Illinois. Lots of historical and scenery attractions, but the hills both in town and out really limits cycling. The Grand Illinois Trail passes right through town but is at it’s worst hill wise.
If Ragbrai ends in Dubuque this year, I will consider a self supported ride on the GIT to get home. The ebike will be a real asset this time around.