One sharp bit at the wheels damaged the skin at her ankle and she couldn't do anything for weeks to recover. It was a very serious problem caused by thoughtless design.
And we are in New Zealand which is better than many places. It is terrible watching people struggle in other countries (or lack access to the simplest requirement).
Good usability is hard enough to find for the smart and strong.
It is extremely hard to find for the weak and infirm. Especially when supplied through government services!
Finding her a wheelchair was hard because she is tiny and needed a teen sized one. But everything available second-hand or through our social services was designed for heavier people with wide arses (imported chairs?). Luckily found a wheelchair manufacturer in my city that had one designed for a teen on special (end-of-line - not manufacturing standard wheelchairs any more - changing to focus on expensive specialist sports chairs).