It takes all of two minutes of Wikipedia reading for me to understand why this isn’t simple; why it's actually extremely not simple! If you ignore the incumbency, the regulations, the training requirements, the retrofitting, the verification, the international coordination, and the existing unfathomably reliable systems built out of past tragedies, then sure, it’s "simple". But then, if you're ignoring those things, you’re not really solving the problem, are you?
Those are excuses and encumbrances, not reasons. If they are so important, it leads to a question: what existing automated systems can we improve by adding similar constraints?
If these are just "excuses" and not "reasons," then explain how you have determined them as such.
I would like to say, "Because knowledgeable people have explained the difference to me." But again, this has come up before, and no explanations are ever provided. Only vague, reactionary hand-waving, assuring me that humans -- presumably not the same ones who just directed a fire truck and an aircraft onto the same active runway, but humans nevertheless -- are vital for safety in ATC, because for reasons such as and therefore.
There you are doing it in order to avoid engaging with the substance of what people are saying.
There is no substance in the replies. There never is. Only unanchored FUD.
"Because it's always been done that way, and that's what the regulations say," will not be accepted, at least not by me.
(Really, my question is more like why humans will still be needed in the loop in 2036. If we started automating ATC today, that's probably how long it would take to cut over to the new system.)
If these are just "excuses" and not "reasons," then explain how you have determined them as such.
This is just not how complex systems work. N of 1 events happen regularly, which is exactly what makes them challenging.
You simply asserting every scenario has been seen before does not actually make it so.