This article seems to do a decent job of summarizing what Disney gains and loses by being their own government. Looks like they saved about $10 million in taxes and fees in 2020 because they do not have to pay impact fees in developing their properties.
Forgot link to article…
https://allears.net/2022/04/16/what-would-repealing-the-reedy-creek-act-mean-for-disney-world/