Netflix (and most other streaming services) don't use a centralized group of servers to deliver content. They have thousands of servers (many cloud based on Amazon AWS, etc.) that function as what's called a content delivery network (CDN). The server you connect to is highly dependent on your geographic location, ISP, and device type. My streaming last night via Roku on ATT Fiber was terrible, but perfect on my phone (with Wi-Fi turned off) over T- Mobile. By doing that, I was likely forcing a connection to a less loaded delivery mechanism.