Lets see what the numbers say when 2022 attendance figures come out. From 2015-2019, attendance at MK only fluctuated by about 400k. Pandora did add around 3 million people, but that had stabilized after that one year. Epcot has also stayed very stagnant by attendance, even with the addition of Frozen Ever After. DHS, saw somewhere between 200k and 600k people added for Toy Story Land. My suspicion is that attendance is not the main driver in why the parks feel as crowded/lines are as long as they are. In other words, they don't need to control the crowds more in terms of limiting attendance, they need to address the reasons it feels so much worse.