It’s a case of strengths and weaknesses-
The human brain is slower and error prone (when compared to AI), and multitasking can confuse/overwhelm it. It is, however, much more flexible and much better at responding when things go wrong.
A computer is fast, can multitask and does not make errors (when programmed correctly), but it is awful when things go wrong/stuff it dosen’t expect.
That’s why FBW aircraft were developed with advanced systems- under normal operations the pilot’s workload is greatly reduced, however when stuff goes wrong (as often happens in aviation) you’ve got humans there to sort it out.
I think much of the fear comes with that fact- there’s little to help when stuff goes wrong, without a human there- the difference to humans is that computers are getting more and more advanced, and while I can’t see in the next decade or so many pilots being replaced by machine, who knows where we’ll be in 50 years time.