It seems likely that the miles put on a "commuter bike" used for commuting twice a day for 10 years are within shouting distance of the miles put on a bike used

It seems likely that the miles put on a "commuter bike" used for commuting twice a day for 10 years are within shouting distance of the miles put on a bike used for several hours of deliveries every day for 3 years. The company is incentivized to get the most out of their investment. If the bikes can be maintained economically by staff mechanics, they will be — and these vehicles ought to be simple enough devices for mechanics to squeeze a long life out of them. If there's a difference, it would be in the lack of an ownership mindset by the riders: they might abuse them akin to how drivers abuse rental cars.