We don't know this for sure, but whatever it is, Toxicator is the first entirely new and original project since Wicker Man.
Having said that, the casual visitor doesn't know that Nemesis Reborn is just a retracked Nemesis. The casual visitor doesn't know that The Curse al Alton Manor is a Haunted House / Duel: The Haunted House Fights Back refresh. To the casual visitor, these are entirely new attractions. That's how they've been marketed. The casual visitor isn't aware of the individual ongoings at Alton Towers, they're not aware of what's necessarily come and gone.
If attendance is down, it's not because of marketing or lack of "new" attractions, it'll be because of awful weather, cost of living and general lack of leisure spend across the board.
We only think it's because of poor operations, or poor food, or poor trip advisor reviews, or lack of new investment, because we are invested and care to find this stuff out. If anything is affected by any of this, it's return and repeat visits by visitors who do not hold a pass of some description.
Since COVID, spend on outdoor leisure is down across the board. Spend on streaming services, digital purchase, gaming and delivery food is up. Spend on physical online purchases, or "trending" F&B outlets is also up. Traditional days out such as the cinema, bowling, theme parks, historical attractions, paintballing, museums and tours, have seen revenue drop dramatically.
We, as a society, have changed the leisure activities we see value in. Sadly outdoor theme parks appear to be dropping off.