This really has nothing to do with aviation. DHL has tentacles that run all over the supply chain, and all they're doing here is setting up some system of little mom-and-pop messengers (read as el-cheapo independent contractors) to do home deliveries in urban centers -- which a million other companies, including Amazon, already do.
Actually, here in NYC, Amazon relies much-more-heavily on the USPS because they are much-more-efficient in this level of density. USPS literally backs a pretty-large box truck up to my 500-unit apartment building every afternoon, and disgorges around a hundred Amazon, Target and other parcels arriving through its Parcel Direct workshare. Then that truck goes next door and does the same thing. Then it's empty and goes back to the Post Office for more. Try doing that with a guy and a minivan.
This "bunch of little providers" kind of operation is exactly what DHL set up for KFC in the UK -- and we all saw how well that has worked out. KFC only even has basic functionality in its UK stores right now because all sorts of supplies are now being shipped directly to the stores from manufacturers -- bypassing the DHL imbroglio. KFC took an efficient, reliable, redundant system using Bidvest-owned trucks and Bidvest union drivers, and replaced it with this cheapo mess -- and deserve what they get.
So this DHL thing in urban centers will probably end up carrying some Internet home deliveries, but it's not anything unique or likely to earn a substantial market share. It's just one more little bit of potential income.