> the bottleneck is no longer writing code
The bottleneck has never been the writing of the code. It's all the rest that takes the majority of the time. Of course, it is often the writing which lets you expand your understanding or your awareness of challenges and pitfalls, which then puts you back on the drawing board.
This. We’ve just moved the bottleneck from during writing the code to reviewing. The failure mode here is that you can choose to just do a light review since the code “works” but if you had to write the code yourself you would have been forced to consider the design choices and broader implications of the code more.