The programmatic requirements usually come from the parks.
Walt Disney Imagineering definitely shares blame for their out of control costs. Weis tried doing Shanghai Disneyland on more of a Universal Creative model of greater delegation (which is less true today than it was at the start of the decade) and it didn’t work. Really cutting through the red tape is going to require someone with the knowledge and power to really hack away at the bureaucracy that has built up over decades (Gurr complained about this in the late 60s) at Disney and for that not happening I blame Iger. Iger is the one who doesn’t like theme parks and wanted to jettison them as part of his efforts to refocus Disney on its core competencies and he continues to not just meddle but place in charge people who share his lack of experience with the industry. Chapek is doing what his boss wants in ways that he can understand. He’s pushing smaller projects with franchises because they the things his boss wants: franchise attractions for a [relatively] lower cost. Really fixing the problems would be empowering someone to cut a lot of people out of the process, people who are often there initially for some legitimate reason but the sort of person who is going to understand the industry and process well enough to be able to make such decisions is someone Iger would not respect or trust.
And it’s really weird that I named four people in the above, all of them Bob.
On the one hand, it's great that the leadership has finally decided the parks need investments and have allocated funds for major additions to every park. However, it's also clear that the leadership lacks any expertise to know whether they're getting any sort of value for the money spent. The high-level decisions reflect a lack of understanding of the basic tenents of what makes theme parks successful, and the follow-through shows an incompetence of menu planning. It's not that the decision makers don't care; they don't even understand what it is they're making.
The rate at which WDI blows through budgets is simply unconscionable to anybody with a nominal understanding of the design and construction industry. Their budgets are orders of magnitude higher than their peers, yet they frequently include parts that are unfinished, lackluster, or deferred to an ever-mythical Phase II. Fans often like to claim these shortfalls were due to "budget constraints," when it's actually due to poor management of outrageous amounts of money. Competent leadership could easily right this ship by cutting the excess, but there's been a constant revolving door of leaders with no expertise in the industry for years.
Nobody wants to be the bad guy that tells the creative team that their designs are unreasonable, so instead the budgets keep growing, attraction capacities keep dropping, and the return on investment disappears. The parks sat stagnant for so long in the last 2 decades because it was impossible to justify the expense of adding anything at WDI's price. A leaner process wouldn't just reduce the cost of new projects, it would also incentivize ongoing investment as it's far easier to justify the cost.
Yes, something needs to be known to get started, but it is not always the final amount. Even then, budget is not the problem. Walt Disney Imagineering just spent an Expedition Everest amount of money on Pixar Pier.
If I'm not mistaken, Everest was $100M (in 2006), and Pixar Pier was in the $225M ballpark (in 2018). Obviously inflation comes into play (around 25% in that period), but they spent well over the price of Everest for an aesthetic redo that adds literally nothing of substance to the park. It was a paint job (that somehow managed to miss large portions of the coaster), some new signage, and little more.
Meanwhile in Epcot they're building a rollercoaster that's reportedly budgeted somewhere around $600M, which is approximately the budget of DCA in 2001, or half of EPCOT Center in 1982 with all of it's massive associated infrastructure elements. This new roller coaster will surely have some nifty whizzbang features, but none of that can justify the absurd cost, which is even more embarrassing when you factor in that it's reusing the largest single-roofed facility ever built in a Disney park for little more than an anteroom. Every element of that project is indicative of the waste that's rampant at WDI, from the monetary cost, to the opportunity cost of the existing facility and expanded footprint, to the absurdly long timeline. None of that gives me any confidence in the organization to work with any level of efficiency.
If a government program spent funds this poorly, it would be subject to endless legislative investigations. But instead Disney leadership keeps shoving money to WDI hoping it will solve all the problems, without the most superficial understanding of how or why it's being spent.