I think the point Andrej was making here is that in some areas, such as self driving, the cost of failure is extremely high (maybe death), so 99.9% reliable doesn't cut it, and therefore doesn't mean you are almost done, or have done 99.9% of the work. It's "The last 10% is 90% of the work" recursively applied.

He was also pointing out that the same high cost of failure consideration applies to many software systems (depending on what they are doing/controlling). We may already be at the level where AI coding agents are adequate for some less critical applications, but yet far away from them being a general developer replacement. I see software development as something that uses closer to 100% of your brain than 10% - we may well not see AI coding agents approach human reliability levels until we have human level AGI.

The AI snake oil salesmen/CEOs like to throw out competitive coding or math olympiad benchmarks as if they are somehow indicative of the readiness of AI for other tasks, but reliability matters. Nobody dies or loses millions of dollars if you get a math problem wrong.