However, code quality is becoming less and less relevant in the age of AI coding

It actually becomes more and more relevant. AI constantly needs to reread its own code and fit it into its limited context, in order to take it as a reference for writing out new stuff. This means that every single code smell, and every instance of needless code bloat, actually becomes a grievous hazard to further progress. Arguably, you should in fact be quite obsessed about refactoring and cleaning up what the AI has come up with, even more so than if you were coding purely for humans.

Even non-frontier models now offer a context window of 1 million tokens. That's 100K-300K LOCs. I would not call that a limited context.