Universal has to offer ‘reasonable accommodation’ for those with a disability as defined by the ADA. (They can also offer to those with conditions not defined by ADA, but that is optional)
To have a disability under ADA, the ADA defines a person with a disability as a person who has a physical or mental impairment that substantially limits one or more major life activity. This includes people who have a record of such an impairment, even if they do not currently have a disability.
So there are many challenges people may have that, while they are quite real (like having to stand in line for a long time when you have bathroom issues), they are not considered a disability and thus businesses are not required to offer an accommodation.
I’m glad you found a way to be able to enjoy the parks. I miss at Disney the old fast passes. With my 3 I could minimize long wait issues for some of the longest lines.