A PM or QA can sign off only on process or outcome quality. They cannot replace the person who actually understands the architecture and the implications of technical decisions. Responsibility is about being able to judge whether the system is correct, safe, maintainable, and aligned with real-world constraints.
If AI becomes powerful enough to generate entire systems, the person supervising and validating those systems is, functionally, a developer — because they must understand the technical details well enough to take responsibility for them.
Titles can shift, but the role dont disappear. Someone with deep technical judgment will still be required to translate intent into implementation and to sign off on the risks. You can call that person "developer", "AI engineer" or something else, but the core responsibility remains technical. PMs and QA do not fill that gap.