One reason for the decline is that over 250,000 per month have been canceling cable subscriptions. That’s over 3 million per year. We just did yesterday. Done with the $160/month Comcast bill for shows that are now more commercials than content and On-Demand no longer allows fast forwarding through commercials. Movie costs for On-Demand are now 1/2 the price to just buy the DVD ($5 to $8 On-Demand rent, $14 to buy).
More shows are now proprietary to services Netflix. These shows are not on cable. Cable is dying fast, real fast. Production companies find they make more money on paid services than through cable. Cable limits what is shown while Netflix, and others, allow far more shows.
Football is carried on primarily cable. They had better find more outlets.