Football is a terrible sport, for a lot of different reasons. I have been addicted to the NFL for 40-something years, and I can't quit watching it, even though I know it's bad. I have cut down a lot though. I used to get Sunday Ticket, but I stopped that a few years ago. I also used to pay for the online video of games after they ended, whatever that's called, but I don't do that anymore either. I won't be giving anymore money to the NFL.
Like I said, I still watch and follow it though, mostly for social reasons and addiction reasons. I wish I could totally boycott it but I can't. Watching the NFL makes you a worse person, but luckily watching baseball will mostly cancel that out.
If they want to try to fix the ratings, they could shorten the play clock to make teams run more plays quicker, and spend less time in huddles and less time waiting for subs to hurry in and out. That would greatly improve the pace of play, which needs fixing badly. Coaches would hate it, because they are now totally dependent on shuttling 4 or 5 different players in and out on every single play, but all that substitution doesn't do anything to make the game more enjoyable to watch.
Of course they need to have fewer and shorter commercial breaks but I can't see the greedheads of the NFL doing anything meaningful about that. Someone mentioned soccer, the main reason watching soccer is so much better than watching the NFL is that there are virtually no commercials interrupting the play when you are watching a soccer game. Lots of commercials before the game, at halftime and after it's over, but no sitting around in the middle of the game for 3 or 4 minutes of commercials.
Obviously the catch rule needs to be fixed. What kind of league can't tell you what a catch is in one simple sentence? It goes beyond that, though. The rules are too complicated, nitpicky and there are way too many of them. They need to throw out about half of the rulebook. That is another thing that won't happen though. The league is all about nitpicky rules, so if anything they will probably add even more 'gray area" rules and make more of a mess of things.
Like offensive holding: everyone knows that holding happens on every single play. But it is only called once in a while, basically at the random whims of the ref. The same hold will be ignored on one play that goes for a touchdown, but then the next time it will get a flag, wiping out the other team's big play. It's ridiculous. They probably should just make offensive holding legal and be done with it. That would at least be more fair and consistent than any ref could make it. Give the defense a corresponding break, like making pass interference 15 yards or something. The point is they need to cut back on rules and make the refs much less impactful in the game, and also reduce all the flags flying after every play.
There are many reasons for the drop in ratings, not just one or two. And I actually hope the NFL's ratings decline continues and even steepens. That would be better for me personally and for American culture, and it would be the only way that any changes would come that would make the game better. It probably won't happen, though. There's lots of dumb people out there and the NFL is made for them, so they'll probably come back.