SLF appears after a long time lurking...
There will come a time when the general opinion will be that flying is too dangerous to be entrusted to the control of pilots. Its a good few years off, beyond my lifetime I'd have thought, but it will come, of that there is zero doubt.
Computers are already better at operating planes than humans, have been for years, and having read this entire thread, I don't think anyone has stated an opinion to the contrary. Every example of "humans being better" is an example of when it's all gone wrong, and the pilot has bailed the automation and/or the aircraft out.
Could a fully autonomous aircraft have "done a Sully"? Unlikely.
Despite this undoubted fact, it is also a fact that losses are caused by pilots. At some point in the future, the losses due to automated aircraft being unable to get themselves out of a mess will be less than the losses caused by pilots. And that'll be the time when the air gets segregated into "pilots allowed" and "pilots not allowed" airspace. The change, when it happens, will happen with breathtaking speed.
It's already been stated above: the autonomous planes don't need to be perfect, they just need to be, averaged over the years, just better than pilots.