They already tried that, they kept the park reservation system in place that they put in during Covid for a period of time post Covid to limit the number of people in the park far in advance of the actual day. This was done because they let go a whole bunch of staff because of Covid then couldn't get them back so had reduced ability to soak up visitors pre Covid.

It was an incredibly contentious choice as it meant to had to plan the exact park you wanted to go to up to 12 months in advance of the date you going. Disney has become a planning nightmare, its a hobby in its own right to manage properly and if you don't do it then you have an objectively worse experience than those who do during any remotely busy time.