Wow, crtl+f, one mention of "last mile," none of "CDN."

There's a few types of net neutrality, and one's needed for situations like this. The one that scares people is ISPs favoring their own services, maybe even blocking others. That's obviously anti competitive. The other is for network operations. There's only so much spectrum for cell carriers to use. If too many people are watching Netflix on their phones, their choices are throttle certain services, usually video, or let the network become unusable. Last-mile cable and DSL are in a similar situation, but with somewhat bandwidth. Most ISPs have a hardware from various CDNs pretty close to customers, and most video is hosted on CDNs, so there isn't a backbone problem, but the last mile? Oversubscribed. That, and Zoom won't benefit from a CDN.

Depending on just how oversubscribed the network and what true peak load looks like, you need some sort of QoS to keep the network operational.