The submitter is supposed to be the good programmer; if not, then maintainers may or may not review it themselves depending on the importance of the feature.
And yes of course they need to be able to write the code themselves, but that's the easy part: any good developer could write a full production OS by themselves given access to documentation and literature and an enormous amount of time. The problem is the time.
> The submitter is supposed to be the good programmer;
And how will that be assured? Everyone can open a PR or submit a bug.
> The problem is the time.
But not the time spent TYPING.
The problem is the time spent THINKING. And that's a task that LLMs, which are nothing other than statistical models trying to guess the next token, really aren't good at.