One problem that gets overlooked is the stale presentation and structure of the show. Raw today might have more money pumped into it, a PG rating, and the faces on the screen are different, but it's effectively the same show it was in 1999. But the TV landscape has changed so dramatically; there's so much quality TV for all demos that it gets harder and harder to justify watching Raw over other things unless you're a lifelong fan.
They need to change up the whole look and feel of the show. Probably starting with accepting that kayfabe is dead and using that to change their philosophy on how they build characters. Not treating it more like sport - everyone knows it's not - but leaning more into the fact that it's a scripted show. Look at things like Lucha Underground or the Broken Universe. WWE doesn't need to copy that stuff exactly, but it might be the direction they need to consider.
Their current product is too stale; no sense of style or identity. And while people want to put that on the talent - debateable; I'd say it's case by case - I think it boils down to the general philosophy running the entire show. The overly scripted promos, the constant insertion of corporate speak into promos and commentary, the overly clean look of everything, the "WWE style" that limits performers in the ring. It all adds up to a unexciting product.
Also, for all the hashtags and whatnot Cole screams at me every week, they suck at utilizing social media to galvanize their current fanbase and entice new viewers. Shows like "Game of Thrones" and "The Walking Dead" have shown that having a loyal social media fanbase talking excitedly about your show can work wonders for attracting viewers. However, WWE is so driven by contempt for their fanbase, so bad at responding to audience feedback, and so incapable of understanding current media trends that most of what you get on Twitter and the like is people complaining about the show. The end result is that they're losing viewers while the channels they could use to start building a new fanbase aren't doing that.
Maybe all of this changes once Vince is out of power, maybe not. NXT is good, but if it's a case study on HHH's vision of wrestling's future, I'm doubtful it's going to do much but satisfy people who were going to watch anyway.
Also none of the current crop have any charisma or stage presence.
The Rock
Stone Cold Steve Austin
The Undertaker
Nick Folley
Big Show
HHH
Chyna
Jericho
Kurt Angle
On any given RAW show in the 00s this was the line up, there was always something well over the top going on, and when there was a slow episode the next one would be massive. Sometimes it was better than the PPV. But now it is too clean cut almost, we wont get anyone like these people again, John Cena was a modern day "The Rock" but there has been nothing to fill the void of campy villans (Undertaker/HHH/Chyna), All American Heroes (Angle, Nick Folley), and people who just mess with things fro the shock (Big Show/Steve Austin
If these guys came into WWE today:
The Rock - Would still be Rocky Mavia because Vince ain't ever gonna admit he was wrong. Pushed to the moon despite fans pure hatred of him.
Stone Cold Steve Austin - Would have been future endeavored after he failed to get over in the midcard as The Ringmaster. Smarks would complain he never got a chance
The Undertaker - See: Bray Wyatt. For Kane's fate, see Erick Rowan/Luke Harper.
Mick Folley - Midcard joke character
Big Show - probably doing the same thing he's doing now, minus the legacy that legitimizes him. Endeavoured after five years or so
HHH - Probably okay cause he'd politic his way into Vince's heart. Even in this alternate timeline, HHH finds a way.
Chyna - Actually probably okay given the current state of the women's division. Would still be jobbing to the horsewomen more often than not, tho.
Jericho - Would be treading water in the Crusierweight division
Kurt Angle - Would be over huge in NXT, immediately ruined on the main roster
I'm not saying the current roster doesn't have it's problems, but save a few talents with luck on their side, no amount of talent or charisma is going to overcome the problems at the core of WWE's modern product (writing, structure, presentation, etc).