As the cost of code gen approaches 0 the cost of the test suite actually grows. Not just in definition, but execution.

An MP3 decoder for a single target doesn't really run into that complexity, a UI components library for (Linux, Windows, macOS) * (x86-64, ARM64) suddenly has a 6x multiplier on what was already something with waaay deeper dependencies and integrations than MP3.

At least that's what I've noticed vibing my DE without external libraries. It went really fast when the complexity was small because most of the work was in adding code. Then it started taking longer to build and test, even with optimized builds and tests, than it took for the AI to do its part.