A bit is not a bit. Some bits actually are cheaper to deliver than others.
The notorious Comcast/Netflix case was certainly not motivated by transit costs, since Netflix offers video content free to any ISP - see https://openconnect.netflix.com/
Also, because of things like edge caches, there are bits that have to travel a shorter distance, and interact with less hardware, than other bits.
Your GE microwave doesn't require that it gets electricity from a GE power turbine. All watts are the same in that sense. The watts can come from a GE generator (in the town over) or a westinghouse generator (in the local town). It doesn't matter.
But a youtube application does require that the bits come from youtube servers. Youtube cannot use bits from vimeo, and because of network topology, the vimeo bits might be more costly for the ISP to deliver than the youtube bits.
From my perspective, along the last mile a bit is a bit. The fact that they may have some back-bone infrastructure that optimizes delivery of traffic to an edge-node for youtube or Facebook doesn't really apply to me (e.g. it is not something I control). The fact that e.g. Comcast and Facebook can do a deal that monopolizes in their favor vs. other social networks/ISPs is not exactly to my benefit. I can't control that deal like I can control adding "a powerwall" in my house.