The NFL represents 22 states. How many states have tier one brand programs? More than the NFL, and the NFL only represents one sport. Amazon is paying 1 BILLION just for Thursday night games. How much do you think they'll pay for a package of nationwide games in football/basketball/baseball? People may be cord cutting, but there is more content than ever before because of streaming. BTW, it's not just TVs that are streaming, but phones, computers, ipads/tablets, etc.
But those 22 states are spread across the country, not isolated to 1 or 1-1/2 geographical areas like the SEC. There are no NFL teams in Oregon, but an average person from Oregon might root for or against Seattle or San Francisco based on like or dislike of the city, state, people he know is the city or state, etc. What affinity is an average person in Oregon going to have for the SEC in the current configuration?
People who still think in terms of the "old model" are completely missing the point. Do you know why "2nd tier" teams are still in play? Because they are still part of the content and tier 1 teams still need to fill their schedules. At some point, the bulk of college money will be made from streaming dominant services, and traditional media will be secondary. It looks like the SEC is gearing up for that and every other conference is still a step behind.
I have stated that the "old model" is in deep trouble. I do think that traditional TV services are going to stick around for longer than you seem to think, but they will have a fraction of the current customers. Streaming will take over and be dominate. Something else might take over in 10-20 years that we haven't even thought about at this point. However, if you look at what is happening in streaming now, it isn't reducing cost and adding flexibility. Marvel, Disney, and Star Wars content are now mostly on Disney+. You can't get Netflix content on other services. You can't get AppleTV content on other services. The result is that things are being "bundled" again. The streaming services costs are rising. I don't believe it will be long before the cost of multiple streaming services will be equivalent to the cost of traditional TV. Some people pool together to share a service and pay less. The streaming services have been working on technology solution to prevent that. They haven't been very aggressive up to this point, but most likely they will get very aggressive about it once those services are firmly established. Some people cycle through the services to save money, since they can be turned on/off every month. Watch HBO this month, Disney the next month, Netflix the next month, etc. At this point, the majority of people are not doing that. If that becomes a financial issue for the services, they will just institute yearly commitments. Streaming services are no longer startup type companies. You have companies like ABC/Disney and Apple who both know how to maximize revenue from their properties. I like the streaming services, but it is inevitable that they will become more expensive and less consumer friendly.
With respect to college football, the big elephant in the room is the subsidies that non-sports fans have been providing to sports. In a future where traditional TV does not exist, a non-sports fan is not going to sign up and pay for college football. That means that the 30-40 percent who watch any sports will have to pay extra for what the 60-70 who don't watch any sports were paying just to keep the exact same revenue. Can the SEC make the same money from their own streaming service if they charge $10 per month? Will people subscribe if they have to charge $50 per month? Can the SEC make the same money if people are allowed to start/stop the streaming service during football/basketball/baseball/etc seasons?
My arguments have not been that streaming of sports cannot work. However, there are issues that will need to be worked through. Fans will want to pay less. Sports programs will want to earn more. Streaming will lose subsidies from non-sports fans. Those are issues that will have to be addressed. My argument has not been that the SEC cannot become a nationwide conference. I have simply said that they currently are not a nationwide conference. If they do not have a presence on the West coast, they will not generate a large fan base there. If they totally separate from the rest of college football before expanding to other regions, they will have issues generating a nationwide fan base. That is difficult to understand in the Southeast. If you go into a local cafe, it is likely that there will be Alabama or mutt paraphernalia on the wall and possibly people discussion SEC football. I don't live in Los Angeles, but I seriously doubt there are any cafes with Alabama posters on the wall, and extremely few discussions about SEC football.