Welcome lyonssv, always good to have more wrestling fans on the forum.
I'm not sure if @prophet called me out specifically because of my tendency to fantasy book, or because of how much I've complained about the shitty booking of Wyatt over the last year.

But I'll try to answer anyway.
First of all, I don't think Wyatt was ever a main event player really. He flirted with it, but the closest he came was fighting Cena at Wrestlemania on the 4th most important match on the card ... and then losing. He never had time to be seen as a main event player.
He was the typical example of WWE pushing people too quickly and then not being able to follow through. They didn't wait until Wyatt got really hot to start moving him towards the top of the card. Before he was even that over, they had him work with Bryan. Then as soon as he started to get a real reaction, they threw him in against Cena. Obviously he couldn't beat Cena, so when he lost that feud it seemed like a foregone conclusion and like he never really belonged in that spot to begin with. And because of WWE's shallow roster, he didn't have a lot of other top level faces to spar against after that, so his falling into obscurity seemed inevitable.
He was like the average Money in the Bank winner. They cash in and win the title before they're ever ready for it. Then they lose the title quickly, because they're not ready to have a proper run. After that everyone just believes on some level that they didn't deserve it in the first place. They end up being worse off after they win the title than before.
As for how to get Wyatt back to where he was before, and maybe even create a genuine main event level performer out of him ... it's not going to be easy. And I don't think it's something they should be trying to do overnight. They pushed the guy to the moon right out the gates and it was never going to work long term. They need to give him some solid feuds with some lower card guys, letting him build more of a character and a body of work. And importantly, he'll have some momentum once he eventually reaches the main event.
His character causes problems too, given that he's quite poorly drawn. The guy has fantastic delivery; they just need to give him some material to work with. I will say that there's no way he can survive without the Wyatt Family. Harper and Rowan have to stay associated with him. Basically his entire character right now is "cult leader". Take away his followers and he's just a guy who talks gibberish.
I've long said that I think the cult needs an actual direction. A set of rules or ideas or principles; a reason for people to follow him. This could be any number of things, but I think the easiest route to take is to make the cult about man's primal nature. Moving away from worldly possessions, delusions of grandeur, etc. We're all just animals, and the wrestlers are hypocrites for spending their time beating each other up for sport and then acting like they're virtuous or special. And this way Wyatt's character becomes even more interesting, because he's the real hypocrite: he mocks the hubris of people who think themselves important, while he's playing the prophet.
I think the "setting free" of Rowan and Harper could be used to establish this kind of angle. It could be that they've passed all of Wyatt's tests: they've freed themselves of their possessions, their hubris, etc. They'll still be members of his army, but he'll have more respect for them and trust them more than the others. This could lead to a fun side-angle at some point if Rowan was to somehow let down the others. He could be bullied by Wyatt and Harper and forced back into the sheep mask.
I think for this kind of angle to work, they need more recruits though. New members to wear the sheep mask and try to learn Wyatt's teachings. For this, I'd take any random midcarder or low card wrestlers who they have no plans for. Just a couple to start out with. Do something creepy and half controversial with their initiations (remember Punk shaving people's heads?) in order to get people talking.
Once the angle was going strong, I'd then start a feud between the Wyatt Family and some beloved midcard face. Someone like Dolph Ziggler would work well. He's liked but he's not too high on the card. This should be a prolonged feud where they try to wear him down and aggressively try to get him to join the group. Ziggler would hold off well against the group for months. Something like Benoit's feud against the Flock back in the day. But in the end, the face finally loses and succumbs to Bray Wyatt and joins the group.
At that point you've established a compelling villain in Wyatt, along with a powerful and credible heel stable. Build this up over months, then you can give him another couple of grudge feuds and after that he may be ready for a title shot or even a title win. And there's an obvious angle to run with after a year, when someone decides to leave the Wyatt Family. Those feuds are always hot when booked correctly.
So yeah, I guess I'd do something like that.
