That is one of many issues.

Put a pin in socio-economic-environmental issues for a second.

AI is good at finding bugs/vulnerabilities. If you're using it for peer programming, the output is 100% what you're comfortable with, while you're still directing what goes where and how. That's right up Torvald's alley. Not every piece of code we write is a masterpiece of complicated art. Sometimes, when we are writing a complicated piece, we are unable to see all the ramifications of each piece in a way that AI appears to be able to see.

From this standpoint, even if we had a LOT more people working on the kernel. We'd amplify problems, especially if the people we threw on the project were more free-hands than artists.

Unpin that socio-economic-env stuff now.

Until tokens cost enough that it's not reasonable, or the AI providers make things dumb enough to save money/meet law/eco demands, most code at most places will likely go through at least a post-cleanup/analysis phase. Everything would be labeled slop.

I don't think, long term, that we're going to have AI writing everything at the level we are even now, but it's not impossible. That's not to say I advocate it or push it forward, but there may simply be no way to stop it if the economics / laws allow it to continue.