I think you need to learn how routing protocols work. I will give you a hint, unless they are using 20+ year old protocols like RIP v1
I don't think you have worked for a real provider for quite a few years. RIP v1 (which is way more than 20 years old) has been effectively dead for years. Every provider has used either OSPF or ISIS for years. A few smaller providers may still use EIGRP, a pretty good proprietary protocol developed by Cisco. This goes back to at least the beginning of the commercialization of the Internet in the late 90s.
But these shortest-path protocols are only used for "interior" routing. That is, within a single administrative domain, like Verizon or Comcast or the University of California at Berkeley. (All of these entities actually have more than one administrative domain to make things manageable or to deal with organizational requirements.)
Between these domain a border protocol, BGPv4 is universal. It is also fairly stupid as it has no information on the interiors of the networks it is talking to. Instead it has a set of metrics that decide what routes to prefer and filter to control what routes are even accepted from neighbors (usually called 'peers'). There are very few metrics. the main one is called AS path length, or the number of administrative domains between points. It is fairly common to edit this path to make one or another path preferred, usually to prefer less expensive paths. Use the free or cheap path if you can and only use the relatively expensive path when there is no other choice. This is a gross over-simplification, but his i not a networking class.
The North American Network Operators Group (NANOG) has several excellent tutorials on routing protocols free on-line if you want to learn more, but, as simple s BGP is, the actual ways it is implemented get very arcane.
Netflix would probably be interested in evidence that Verizon is deliberately limiting traffic. I'm sure that they would be delighted to hear from anyone who can provide things like records of chats or e-mail where Verizon employees makes statements demonstrating this.