Software development jobs will be some of the last to be automated, since they are very mentally difficult.
So is chess!
And chess was one on the first mental "jobs" to be successfully automated. Just because something is mentally difficult doesn't mean it's immune to automation.
Right, there are things that computers can do well that humans find very difficult, like adding billions of numbers together without making a mistake. Chess is difficult, but it's also very narrow in that can be described in a way that turns it into a calculation problem for computers.
Imagine if you could simply tell your computer "Write me a bug free function that does X" and it spits out the code in a matter of seconds. Of course, programming doesn't just require "left brain" skills, it also requires intuition and creativity, especially for higher level stuff like design and requirements engineering. But anyone reasonably intelligent can now become an expert programmer in a matter of months instead of years.
Yes, a lot of what programmers do now is drudgery, and programming languages will continue to get higher and higher level to remove a lot of that, but it will be a while before a person can have the idea of AirBnB and say "Computer, create a service that allows people to rent out space in other people's homes for short amounts of time. Also make sure it's super well architected and scaleable and looks good. Then do a bunch of marketing and get lots of customers. Thanks!"
What you don't seem to be taking into account is that this will simply make the tech elite more elite, and concentrate wealth into smaller group of these tech elite. Sure, when programming is easier more people will be able to accomplish something reasonable, but when I want to visit another city I don't want to use the 54th best version of AirBnB that my cousin created, even if it's way better than what he could accomplish with today's technology. I'll want to use the best version. So now the guy who created AirBnB needs no low level programmers, and he can profit much more himself from his creation, and he can create 20 companies instead of a couple. All the mediocre programmers see their wages fall, and a small elite of visionary product people see their wages rise (until AI displaces them eventually).