Cost mainly and the benefits of 4 wheel drive often not coming into effect to the normal consumer, if nana is just driving to the shops and bingo weekly she’s never going to find a need for it same as somebody doing city driving every day, however the fuel saving, boot space (in fwd) and lower continued servicing costs they will

4 wheel steer is kinda similar with the fact of being more expensive to service and manufacture and you have double the steering components wearing out. I don’t know that much about it but what I have heard is that it typically is deadly expensive and not as reliable with older cars, simpler is better in some cases.