Nobody is going to care about how much code an AI system generates in the very near future, some even now, once everyone understands the scale at which a vector space truly operates at. Complexity is not much of an issue for an AI system.
Abstraction is an issue for every AI coding agent. They are painfully useful, but need constant badgering in the right direction.
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.