Like superficially.
I suppose US vehicle designers have found that designs which harken back to the US's apogee are popular.

I think most of the cabs for these trucks are probably decades old designs.

There's very little need to design newer looking ones for trash trucks.



More innovation (prettier trucks) with semi-truck trailers because those are bought by owner-operators and aero improvements can save a lot on operating costs.

I somehow doubt aerodynamics helps at all for garbage trucks, since they are spending most of their time braking, idling, then accelerating at walking pace.

I think an all-electric mode with regenerative braking and a ultra-low power idle mode would be best for this. Maybe hybrid engine that uses gas just for the speedy part where you go to/from the dump.