frfr If I was a DM and someone wanted to be wheelchair bound, I'd let them.
Then they'd have to roll to get up the stairs, probably at disadvantage. Why? There's no ramp. Then they'd get outside, and there'd have to be a difficult terrain roll. Why? The road isn't paved, so it's tore up from the foot and horse and cart traffic.
No, I would have to tell them, this isn't discrimination, these are the actual difficulties you would face in such a world.
Though, I have never come across a disabled person who roleplays being disabled. They always seem to be the one to be like 'why would I want to be disabled in my fantasy game?'