My wife and I both qualify for a handicapped parking placard, but I don't need one since she got her placard first. She has two artificial hips and if they aren't bothering her, she can walk for miles, but you never know when that might not be possible. She often does carry a cane just in case.
I had a liver transplant and spent 3 months in the hospital afterward and was bedridden and had to learn to walk again by building up my strength. I already had bad knees from standing watch on steel decks for years. Before I even had the transplant, I had to use the electric carts to shop, but I have mostly recovered.
My daughter was discharged from the Army because she tore her ankle up so badly that the surgical repairs even failed. She has VA 80% disability rating because she cannot stand for extended periods, but she can literally walk for miles.
My son and I attended the Grand Ole Opry tonight in Nashville. While parking, they directed me to the handicapped parking lot, separate from the others. When we parked and got out of the car, a gentleman in a golf cart pulled up and told us to hop aboard as he would take us up the hill to the show. My son is a 100% disabled vet. The Opry has elevators that we could have taken all the way up to only a small set of stairs to out nosebleed seats. When we came out, the elevators were busy so I walked down 4 huge flights of stairs to get out, and then down a about 75-yard-long ramp back to the parking lot when the line for the golf cart was too long and we could walk, so we did. We didn't want to make people worse than us to wait.
You can't tell by looking at any one of us that we have a handicap, except when my wife carries her cane.