Technically, it seems like aircraft are closer than cars. Probably in the vehicles themselves and definitely with respect to external control systems.

In terms of public acceptance, I wouldn't be surprised if you have the psychology of it right, especially when you consider that for commercial flights you have to get buy-in from nearly all of your potential passengers or you will lose them to competitors. Maybe there will be a period of automated and non-automated flights with the latter more expensive.

For other uses like cargo and business jets, adoption could be much faster.