This is the part I disagree with.
In a non-agentic world, the expert and the programmer are two different people. If the expert finds a bug in the software, they have to describe that bug, send it over to a programmer to fix, wait for a new release and until that scenario occurs again, realize that their description was actually wrong, send a corrected description, rinse and repeat for a few iterations until the bug is finally fixed for good.
In a world of agents, the expert finds the bug, asks the agent to fix it, realizes that the fix is incorrect because of sloppy thinking, does a few iterations until the feature works correctly, and that's it. Bug fixed; with 10 minutes of work instead of a few weeks.