>single development, in either technology or management technique, which by itself promises even one order of magnitude improvement within a decade in productivity, in reliability, in simplicity.
To take an easy example:
>We've got GIT, which is a huge improvement over ZIP files of source code stored on floppy disks.
This is a huge improvement over the previous flow of passing around ZIP files, but it doesn't yield an order of magnitude gain in overall productivity for a dev team. For it to yield a 10x improvement, it would mean that programmers were spending at least 90% of their time passing around source code.
It's for sure an order of magnitude improvement on the subtask of code collaboration, but it's not a silver bullet in itself.
I think collectively there have been advancements that have produced an order of magnitude improvement in dev productivity, but Brooks' claim was that there would be no one thing that eliminated 90% of a developer's work.