Major League Baseball would like to talk to you about that.
Frankly, the fact that I can almost always find an illegal stream of quality as good as ESPN's streaming, I find it difficult to believe it's that hard to do. And the fact that several major professional sports are doing it, mostly using MLB Advanced Media, tells me that ESPN can do this if it wants.
The problem is the economics of scale and advantages of bundling, not live broadcasts.
EDIT: I should add that not only is MLB's streaming as good as TV, it's better. I can pause, rewind, see multiple angles or even watch more than one game at once. If it weren't for draconian blackouts (see, there's economics getting in the way again) it would be the only way to watch baseball.
Its difficult, but not impossible by any stretch - the BBC stream the Olympics live, and have done for several iterations now, without seeming to have any major problems.
They've got an even harder problem, in 2012 they were providing simultaneous live streams from 24 separate events at times. Sadly I can't find any statistics on just how many viewers watched something like the 2012 opening ceremony, but I'd be surprised if the numbers weren't comparable to the Super Bowl.
The 2012 Olympics were an absolutely huge undertaking - the BBC went as far as creating a mock Olympics to test traffic and server load and at its peak shifted 2.8 PB of data a day. When Wiggins won gold, they were shifting 700GB/ps. No doubt things have come a long way since then - but I get the impression it really was no mean feat.
- If you're watching a game on say a 50 minute delay, the live CDN gets shut off about 10 minutes after the broadcast ends and you actually can't finish the stream for 40 minutes while they move it over to the VOD CDN. So if I have a meeting or whatever in the 3rd, it'll shut off in the 7th. I confirmed this bug with a friend I know there.
- Most of the players can't remember where you were in stream across crashes and definitely not across machines.
- Player constantly resets settings and switch to showing you the scores.
- Not technical but the audio recaps ALWAYS use the broadcasters from the winning team. So no need to watch a 7 minute recap of the game, first word uttered by the broadcasters tell you who won.
- Player won't re-upgrade the stream quality after it downgrades it.
- Player can't recover from a stopped stream.
- Player is in flash still on desktop. Which is blocked by my work firewall.
- Only their phone support does anything.
- They don't trim out rain delays, so you can sit there for 5 hours on a VOD during a rain delay. You "could" skip to the next inning but you have to turn on spoilers if it happens mid inning (which happens often).
- You can jump to the top and bottom of most innings. Playstation and desktop apps often lose their minds and restart.
- You can't skip past pitching changes even though they're a standard 2 minutes.
- Watching the tv broadcast but changing to a radio audio crashes the ps4 app.
- Fire TV app, when you select "From Beginning" on a stream you're starting late always jumps live. If you chose live, you can't rewind at all.
- If network is down the app loads that there are no games on the calendar and leaves it cached as empty. You have to restart the app to fix it.
- They show very little of the color commentary from the field, only booth stuff.
- Watching a vod you have to fast forward 12-18 minutes to find the beginning of the game.
- Inning start markers often are often placed as far as 2-3 batters in. I've seen 2 outs in before.
- The web version has tons of issues, I mostly use the ps4 app as it's more stable.
- The mobile apps require you to have full GPS turned on, which is great for battery life when you're already streaming.
- You cannot time shift radio broadcasts of games. You can't pause them either.
- If a radio broadcast buffers to much it just stops playing and you have to use the app to restart it.
- Getting to a broadcast on mobile requires jumping through a bunch of hoops all trying to show you the score.
- You can't time shift on mobile.
- I CANNOT STREAM THE AUDIO OF THE GAME AT THE STADIUM BECAUSE IT'S BLACKED OUT. NOR CAN I WATCH THE GAME I AM SITTING AT FOR THE SAME REASON. I did sit at the 2nd to last mariners game while watching the Cardinals game and separately the Giants game on my laptop and phone. Which was fun.
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.
Frankly, the fact that I can almost always find an illegal stream of quality as good as ESPN's streaming, I find it difficult to believe it's that hard to do. And the fact that several major professional sports are doing it, mostly using MLB Advanced Media, tells me that ESPN can do this if it wants.
The problem is the economics of scale and advantages of bundling, not live broadcasts.
EDIT: I should add that not only is MLB's streaming as good as TV, it's better. I can pause, rewind, see multiple angles or even watch more than one game at once. If it weren't for draconian blackouts (see, there's economics getting in the way again) it would be the only way to watch baseball.