We will see SINGLE pilot airliners carrying PAX in our lifetime but we will not see fully autonomous aircraft flying people for a very long time. My son might see fully autonomous but it won't happen in my career. Don't believe me? Who was flying that capsule that Elon just landed on the barge? Rockets are far more dynamic than any airbus or boeing.
Once the accountants figure out a way to justify the costs it will start happening. The first place you'll see autonomous flight modes will be in freight, once they've proven the concept it will happen in the 121 world rapidly. Again, we're talking single pilot airliners with a secure datalink to the ground.
The aircraft will require very few modifications since 50 year old aircraft have been modded to fly as "drones" for both the military and private entities. Unless you've got intimate knowledge of how these technologies work and how good their redundancies are it seems like black magic, but it's not.