For the most part the e-bikes are being assembled by very small companies using imported frames. They want to stock as few frames as possible while allowing for different size riders and they are also targeting a price point. What we are getting with e-bikes is something comparable to the bikes sold by Wal-Mart. No need for such heavy frames or such heavy tires. The Vietnames moved hundred of pounds of supplies on simple bicycles and did so in such quantities as to defeat the U.S. military wih all its trucks and cargo planes and helicopters.
It is different than with cars where the range per battery charge depends in part on the weight and rolling resistance of the tires that are used. With an e-bike if it only goes 30 miles instead of 45 miles, most people do not care. Most customers are not bicyclists and think that large fat bike tours look cool even if they will never use the bikes on a beach. It was much the same with the first mountain bikes from Marin which were also crudely built but quickly evolved and shed many pounds. The end result though was that most of the bike production is now in Taiwan and not the United States.
What is a major pain is that very few bike racks will support the 110 to 150 lb load of two e-bikes. Hollywood racks are one of the few and they are on backorder in the USA until June of 2021.