Wheelchairs don’t have disabilities; people do. Unfortunately, many people intuitively think of disability as residing in wheelchairs and other adaptive equipment, and forget that it’s a basic fact about a person and that person’s body.
This can cause a lot of problems and misunderstandings.
For example: Jane uses a wheelchair most of the time, but sometimes walks when she needs to go somewhere inaccessible. That’s nastily exhausting, bad for her health, and comes with a significant risk of injury. Sometimes she does it anyway because it’s important for her to go to an event, or take a class, or do something else in an inaccessible place.
Jane’s sister Sarah is getting married, and has chosen an inaccessible location. Jane decides that it’s important enough to her to go to that wedding that she’s willing to go even though she won’t be able to bring her wheelchair.
All of Jane’s relatives assume that this means that she is ~getting better~, and doesn’t need mobility equipment anymore, even though her disability is not an illness and is not something that can be changed. What it actually means is that she’s having a very difficult and possibly dangerous day because her sister made an inconsiderate choice.
Jane’s wheelchair doesn’t have a disability; Jane does. And when Jane isn’t using her wheelchair, it doesn’t mean that she’s somehow less disabled; it means that her needs aren’t being met.
Or, another example: Bill has a chronic illness. He usually needs his wheelchair to get through the day, but sometimes he’s feeling particularly energetic and decides to walk somewhere. His friend Joe sees him and says “It’s so nice to see that you’re getting better!”. This bothers Bill, because he’s not getting better, and he’s not going to get better, he’s just having a day where taking a walk is an option. Bill would like people in his life who don’t understand his reality to stop making inappropriately intimate comments about his health.
There are many other examples, for just about every disability category. People make a lot of unwarranted and intrusive assumptions about someone’s disability and health based on what adaptive equipment they are or aren't using on a particular day. Those assumptions can cause serious problems for people, and it’s important to stop making them.
Mobility equipment doesn’t have disabilities. People do.