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?
In fact the productivity is already enough high for most of the people to retire early, but due to the existance of money and exchange, this can not be done
Imagine an island with two people Bob and Alice. Bob is very smart and can produce 10 times more products per year than Alice. In today's monetary system, we suppose that Bob will earn 10 times more money than Alice (Money is used as a unit of value)
But that is simply not possible, because Bob's income can only come from his sale to Alice, and Alice have much less productivity thus much less income. As a result, Bob's income is limited by how much Alice can spend
The current solution is government charging heavy tax on Bob and give them to Alice so that she can buy more Bob's products. It also means that Alice get more income than her production, because of Bob's high productivity
Or, government take loan to run infrastructure projects, give Alice enough income to buy Bob's products
Anyway, the core of the problem is: High productivity people can not fully utilize their efficiency due to low demand from low productivity people. Unless they give up some of the productivity for free, there is no way to reach 20% employment
If Bob is not profit oriented, he can max out his production thus maximize the social wealth, but he won't have enough motivation to do so, since redistributing his products to Alice is more like a donation. Money is that motivation: If Bob can exchange all his production into money, he has some motivation to produce more, since money will store value and delay his consumption until a later time. Unfortunately, since Alice have little access to money, Bob can not make money by himself alone