NGL I'd argue there's a certain appeal to "use AI to prototype a feature as fast as possible and focus your engineer hours on building a comprehensive testing and fuzzing plan" followed by a "remove and review everything that can be cut without breaking the tests" cleanup pass.
I do see the appeal, it’s easy to imagine that workflow working, and working well - but it’s hard to how it avoids this fate: https://youtu.be/QEzhxP-pdos
You're describing a problem that's plagued corporate software development for decades. You just get to the "unmaintainable ball of mud" stage faster now. Every few days I spent a while on codebase architecture improvements after landing a slew of features.
That's a leadership failure not a technical failure. If you can't dig your heels in and force time to tidy up technical debt then you need to find someone who can and let them take over as PM.