We are still quite far from the type of automation that will allow for 5% employment. Even if the majority of production is automated, there are still many other components of a goods producing business that may not be automated if they are competing in a relatively free market. Procurement, logistics, marketing, sales, support, R&D, etc. would still require a human component without AI right? Then there are service industries.
True, automation require a lot of R&D, and when complexity raised above certain level, the cost will be higher than the gain. In a highly complex system, a small bug will cause days of delay in automated system, which could trigger a chain of reaction.
But anyway that is the trend, maybe not 5%, but 20%, there should be a framework that can be adjusted based on how much labor is needed to re-allocate the resource to those redundant people. Current solution is printing lots of money to create lots of useless job just to make people get something to do, not a bad idea but far from efficient
So there are a few issues keeping us from going towards this automated economic model.
1) We don't have enough people on the tech/r&d/engineering side currently, so we would need many more people to be educated (in or out of school) in coding, software development, robotics, engineering, etc.
2) What happens to the rest of the people that are useless in the new system? They are the majority.
3) In this system, only companies that actually produce or optimize goods/services are useful - so things like financial services, which don't really produce anything but take a cut from everyone that does produce, will need to
4) How are resources distributed for production? Ideally it should go to the most productive and beneficial options. Then once goods are made, how are they distributed if the majority of the population doesn't make income?
We are currently so primitive compared to the type of world we're dreaming of...I mean like you said, we have the money printer going and engage in war. Could you have any stupider people leading the world? Once you've conditioned an idiot to think he's doing good by killing another person that he's never met, something's very wrong. In the new world, that idiot would need to be programming a manufacturing robot. /end rant.
For the transition, I think the tech companies will have to set the stage and compete solely based on technological innovation. Elon Musk is making a huge push for tech companies to expand into other industries, and I really think when you have brilliant minds, they can take over whichever industry they please.