Not all of Asia, but Thailand is really impossible.
In Hong Kong, Singapore or Japan disabled people are a really frequent sight but in Thailand there seems to be some kind of stigma to them going out as well as the faact that almost nowhere caters for them. My wife recently broke her leg very badly in Hong Kong, she needed surgery and was confined to a wheelchair for 3 months. In Hong Kong the pavements are not too good and it is very hilly so some places were quite aa struggle. However, with some effort and planning we were able to get pretty much anywhere. Shopping centres, subway stops, offices (government or private), parks, cinemas, Disneyland, Ocean park etc etc all have lifts and ramps to cope with wheelchairs. Many busses and taxis are adapted for wheelchairs. Restaurants and most other locations are geared up for the disabled and very often as soon as you appear there are people turning up to direct or help you.
On returning to Thailand there is none of that and luckily we have a car and she was able to walk short distances with a stick by then or she would have been very restricted.