the really noxious combination is local ISP monopolies (most neighborhoods in NYC have only 1 broadband ISP available, for example) with upstream non-neutral internet backbones.

this leads to extreme service reduction and price gouging of consumers, as all the costs of paid prioritization that the backbone imposes on the local ISP get passed right through to the end user.

this is particularly problematic for mobile internet access too, since the mobile data provider is often owned by the same parent company as a large backbone company.