Eliminating 80% of programmers does mean that on paper "output per worker per hour" has increased, but it doesn't necessarily follow that you can deliver faster i.e. the output/hour of the business as a whole might stay the same.
In a degenerate case this might take the form of AGI replacing the lower tier workers but doing the same thing at the same speed.
Mid-term future iterations will quickly get to 10x and beyond.
Also: your math is based on the random elimination of 80% of programmer roles. I was specifically talking about the elimination of the worst 80% of programmers.
By worst, I mean "the least productive" - not "terrible persons".
Not to be a raging egalitarian, but it’s hard for 20% of workers to have enough business context as 100% of workers to be able to maintain the same level of productivity. Things like gathering requirements become massive bottlenecks to productivity.
As people in this thread have stated elsewhere, there’s a HUGE last-mile problem in programming. For this reason having 20% of the programmers we have now might not be the ticket. We may even want to take some of these mediocre programmers we have now and have them do other duties like say, systems administration. In other words, it could be that hours spent programming decreases rather than the number of workers, to allow for higher communication bandwidth.
