One thing to consider is the footage being shot with the actors. With the pandemic, Hollywood was shut down, and understandably so. That, coupled with budgets being upended, massive losses from closed parks, movie theatres, etc., created a perfect storm. Now, the added timing to build buzz and have appropriate ROI for that buzz is a factor as well. In a way, everyone really lost 18 months of their lives.
Also, for what it’s worth, spreading cost over fiscal periods is even more of a practice today than in the 80s. There’s also the consideration of building in an existing park, which is making money, vs a new park that is only spending.