There are a few common sense, logical ways to start fixing things:
1. People don't watch 3 hours of anything but an Avengers movie, find any 3 hour TV show that doesn't fall off over the course of the show. Even live sports has a sharp fall off after a certain length.
2. Segments have to be shorter. If they're not shorter, they need to be more dynamic and quick FEELING, at least. People are going to tune out 100% of the time of boring wrestling monologues that go 10-15 minutes with poorly and dull scripted dialogue. You're competing with 500 more shows than there were in 1998, along with a billion streaming services and general phone fukkery. By the same token, people aren't tuning in for long ass matches where nothing happens. Matches need to be shorter, faster, more compact, and exciting, not full of rest holds. Especially don't run these long ass matches 2 1/2 hours into the show when the crowd is already tired and bored and wanting to go home or go to bed.
3. More crowd interaction in general. WWE has been pushing/forcing talent to ignore the live crowd for so long that anyone who has even the slightest interaction with them or allows for a chant gets over. No one works the crowd anymore beyond heels doing headlocks for heat. You don't even see faces looking to the crowd for motivation anymore. Elias has had 2 or 3 of the biggest reactions in YEARS because he actually interacts with the crowd, he hasn't DONE anything as a character or wrestler.
4. No one has the attention span for these 9-10 months feuds with 25 matches between two guys. WWE has a roster of 500 wrestlers, there's no need to have the never ending rematches. People are going to tune out of the 9th Lashley vs Balor match since March. People especially aren't going to keep watching when there isn't even story beats or progression, it's just rematch after rematch after rematch with no stakes or escalation.
5. Consistent storylines and characters. This should probably be 1. These are scripted television shows. Treat them like it. Write a fukking script. Think shyt out ahead of time, Point A Point B Point C and how you're going to get there, and stick to the plan. No TV show is just changing shyt last second every week even if it makes no sense with what came the week before. Regular TV shows get cancelled when that shyt happens because an audience will not stick around for a show that doesn't make sense.
6. Stop insulting the audience. I don't just mean their intelligence of shoveling constant shyt and trash and expecting them to lap it up, but also having wrestlers and commentators who exist just as Vince's avatars to show his disgust and contempt for his audience.