I can't help but notice that the StreetScooter is significantly smaller than a typical UPS truck. It looks in the size range of a Ford Transit Connect, while most UPS trucks are Utilimaster curb vans that are something like 25' in length. I suspect that the balance of vehicle size and mileage might make this kind of adoption rather difficult for UPS - I live in a city, but not a very dense one, where I'm pretty confident that UPS trucks can regularly clock a couple of hundred miles per day.
Incidentally this city is also in the process of adopting a fleet of battery-electric transit buses, but it's been a very rough process for the same sorts of reasons - very large vehicles that run very long routes in this relatively far-flung city. The buses failure in testing to deliver the promised 270 mile range has been a major issue with them, as the roughly 200 they're able to do isn't sufficient to complete their planned schedule.
In at least some parts of Germany they're more likely to encounter narrow streets where the typical US brown UPS truck might have real difficulty navigating.
I also suspect that the routes are shorter than you might think, because there are a lot of stops and they are not moving all that fast for most of the trip. I suspect most UPS trucks probably average well under 25 miles per hour for most of their travel which would put an 8 hour day around 200 miles. In denser areas like cities it could be significantly less than that. If a truck makes a 1-minute stop to toss a package on your porch then drives half a mile in another minute and repeats, it's still only covering 15 miles and 30 packages an hour.
I wouldn't be surprised if UPS trucks within cities tended to be below 50 miles/day most of the time, and since they control driving routes very tightly they can easily put these trucks only on appropriate routes.
This is a pilot run of 50. Think of them as prototypes. They will use what they learn from these prototypes to build a larger fleet. If they can make these purchase price competitive with their current trucks it will be a huge win.
Different markets have different requirements. The DHL streetscooters are a massive success and are drawing interest / demand from many companies outside of DHL. They kickstarted this when no major manufacturer was willing / able to provide them a solution. The platform seems to be scalable and will be able to provide bigger hulls as well. And they are somehow battle tested now as not all was smooth sailing after launch - as could be expected. The whole white / brown / yellow van users will be the first to jump on EVs for many reasons. Remember that in Germany the federal administrative court will rule on (partial) bans of diesel vehicles in cities...
Depending on how your delivery business is structured (customer density, and what type of driver's license your drivers have) your efficiency may be constrained by (a) driving time/distance, (b) vehicle legal curb weight, (c) vehicle reloading time or (d) at-customer delivery time.
If your company is constrained by (a), (b) or (c) current electric vans will make that limiting factor worse. Post offices are mostly constrained by (d) which makes it easier for them to deploy electric vehicles.
None of these problems are insurmountable, but current electric trucks aren't drop-in replacements for diesel trucks.
Keep in mind this is UPS, a private company, and not USPS, the US postal service. The algebra for private companies doing this is different than the government.
German „Deutsche Post“ is not a government owned company (any more). Listed on the stock exchange with 80% of the stocks owned by other than state owned entities.
Incidentally this city is also in the process of adopting a fleet of battery-electric transit buses, but it's been a very rough process for the same sorts of reasons - very large vehicles that run very long routes in this relatively far-flung city. The buses failure in testing to deliver the promised 270 mile range has been a major issue with them, as the roughly 200 they're able to do isn't sufficient to complete their planned schedule.