You are arguing against something other than net neutrality. I don't know what you're arguing against (sounds like a strawman for socialism), but it's not net neutrality. The purpose of net neutrality, like the purpose of antitrust laws, aren't to subvert the free market, but to prevent bad actors from subverting the free market for their own gain. Nobody's asking Spotify to have every song, because if I don't like what's on Spotify I have tons of alternatives.

Comcast customers (for example) are already paying Comcast to receive bits from Netflix. Comcast wants to double dip that traffic by charging Netflix to send that data to those customers. That's it. If there's no legal impediment to them doing that, they are going to do that. Ultimately, customers end up paying for that- any service that a telecom double dips on will be forced to charge their own subscribers to cover at least part of the difference. So really, it's just more money leaving customer's pockets and being indirectly routed to Comcast. No value is added. Maybe, possibly, there will be some extra resources spent on the telecom side to help a double dipped content provider better distribute their content. But that's not a guarantee and there's nothing preventing them from making such arrangements already.

Net neutrality has nothing to do with whether or not telecoms can build better infrastructure to better support certain content providers. Net neutrality is about making sure telecoms don't double dip, just because they can.