I think it's dramatic to say it's the end of hand written code. That's like saying it's the end of bespoke suits. There are scenarios where carefully hand written and reviewed code are still going to have merit - for example the software for safety critical systems such as space shuttles and stations, or core logic within self-driving vehicles.

Basically when every single line needs to be reviewed extremely closely the time taken to write the code is not a bottleneck at all, and if using AI you would actually gain a bottleneck in the time spent removing the excess and superfluous code it produces.

And my intuition is that the line between those two kinds of programming - let's call them careful and careless programming to coin an amusing terminology - I think that line may not shrink as far back as some think, and I think it definitely won't shrink to zero.