You can most definitely produce high-quality code via an LLM, particularly if you test your code aggressively and review it. Yes there are a lot of shoddy PRs, but that's nothing too new. The problem with LLMs is the amount of code they produce. More code = more garbage. But, that code velocity can be leveraged to increase quality. Through careful design and testing.

Ultimately, I would take LLM code + high-quality multi-strategy testing over human code with little to no tests. And some would say "well that's a false dichotomy". I disagree, before LLMs engineers didn't have the time or incentives to aggressively test. The tests either would not exist, or would be shitty unit tests intended to get an arbitrary coverage percentage. Now, we can write high-quality tests, differential testing, fuzzing, and more, in much less time.