After 22,948 commits, 13,720 bugs and -2,899,391 lines eliminated, I've seen this too but a properly designed AI pipeline's ability to optimize and course correct with a little badgering supersedes any Frankenstein-like outcomes.
Be it abstract or simple, more comments or no comments, adhering to clean code principles or following whatever software architecture you want...
Include style guides, static analysis and formatting tools in the development loop, use skills and hooks properly... I started to have a much better time with agentic coding once I spent time setting things up properly for my projects and writing down how I wanted things to be done.