How is Netflix comparatively easy? The problem isn't the video conversion, that's solved by throwing CPU at it. The problem is distribution... which is the "exact" same problem Netflix solves.
Because it's a preexisting set of files that can be distributed geographic down to closer and closer endpoints in the network. When you're watching Netflix you can just as easily be watching from a pure-fiber connection point to your local ISP that's not reaching across the internet at all. Viewership spikes will be more predictable based on their own choices, preferences, schedules, geographic region, etc. If an interruption happens, it's also very likely going to be isolated to a small subset of users.
With a live broadcast like the Super Bowl, you're talking about millions of simultaneous individual streams at the exact same time period, globally, from a central point, across the network and if there is a problem it's probably going to happen to everybody. The more people that tune in, the harder it gets.
Comparatively, TV broadcasts are a much better option for this type of event. You've got a single broadcast for every channel that people can tap into if they want to watch. The total bandwidth is 1 stream per channel instead of 1 stream per person.
Tapping into the WatchESPN app or others for sports that aren't being watched heavily is fine. Tapping into it for something with very high viewership is an entirely different ballgame (pun intended). The broadcast model is just much better suited to live events.
The difference between ESPN and Netflix is that you have (tens of) millions of people watching an event at the exact same time. This is a similar problem in nature, but the simultaneous nature of the problem mean your solution will be different.
Doesn't that make the problem easier? Send one stream to a network node close to the viewer and then "fan out" the stream from there? No need to worry about 50 different users who all started watching Luke Cage at slightly different times.
Yeah, but for non-live broadcasts you can do this too, but do it asynchronously, and indeed, Netflix does. If you're watching reasonably popular content (Luke Cage, say), you're not getting it from Netflix proper, you're getting it from a a Netflix point of presence colocated with your ISP. It's the exact same "fan out" model, but for most of the transit (the whole part that crosses the open Internet) they can take as long as they want, transfer during off-peak periods, are tolerant of congestion, etc.
Multicast has been in the works for decades but it's still not reliable enough. Partly a chicken and egg problem - sysadmins don't bother checking that multicast works on their networks, because no-one uses multicast.
With a live broadcast like the Super Bowl, you're talking about millions of simultaneous individual streams at the exact same time period, globally, from a central point, across the network and if there is a problem it's probably going to happen to everybody. The more people that tune in, the harder it gets.
Comparatively, TV broadcasts are a much better option for this type of event. You've got a single broadcast for every channel that people can tap into if they want to watch. The total bandwidth is 1 stream per channel instead of 1 stream per person.
Tapping into the WatchESPN app or others for sports that aren't being watched heavily is fine. Tapping into it for something with very high viewership is an entirely different ballgame (pun intended). The broadcast model is just much better suited to live events.