Not a complaint- I love the diversity and inclusivity strides the Sims developers have made.
I get that there will be challenges to adding disabilities, not least that R&D developers like to know what else they can apply the changes to. There are elevators in the Into the future EP, and there are canes in Generations (I think that’s where). So add an option for a larger elevator. Ramps should not pose much more of a challenge than stairs. A white cane among canes should have a few tweaks like “most Sims will get out of the way.
These three changes, as well as low vision and HH/deafness, would be cross applicable to gameplay for elders.
In Sims 3 developers worked out werewolves, fairies and ghosts. I’m sure those were challenging, but not more so than blindness, deafness and wheelchair or crutch dependence.
Adding these options would also facilitate new consequences and challenges for play. Maybe your Sim doesn’t die in a fire but is blinded.
There are not currently different language options, but I think there could be. Braille, ASL, but why not also Simanese, Simgonese, Simabic, Simaranian, Simskrit and Simdu? They don’t have to sound very different, since they’re all fantasy languages. For instance when you lock a door, you can choose which Sims can understand your Sim (only family members, only Sims from abroad, or no other Sims. Or Sims World Languages could be an EP.
I would pay to play a disability EP or a linguistic diversity EP.