The range only needs to cover the period between mandated brakes. Everything over that is wasted weight, as the weight of the cargo and the weight of the truck share a weight budget.
Yeah the range between mandated breaks is way over 100 miles. In the UK it is 45 minutes after 4.5 hours driving, so about 270 miles. But you need to account for the likelihood that there isn't a charger at the break stop. On the other hand the Volvo trucks in this article apparently have a similar range and they're selling so I guess it's worth the hassle.
That’s technically true, I suppose, but dishonest since you imply that those numbers are large enough to max out driving time. You wouldn’t be able to drive to your first mandatory 30 minute break with that range.
Many journeys will be from the distribution center to the supermarket or similar, or even multiple supermarkets, which would really bring down the average.