monozygote And also, many FOSS maintainers/contibutors might be using coding-agents (but hopefully human-reviewed). They might be reluctant to admit it given the taboo surrounding the mere mention of such a thing - just look at this thread.
Not disclosing AI usage is erring on being unethical behavior, so I hope that is not common. I believe the open source projects that have AI policies today that are permissive towards using AI still require you to disclose if any committed code is AI made.
Let's see what the future holds. The researchers developing frontier AI models seem to believe we have hit a wall. Number of parameters and compute is no longer the limiting factor, but availability of training data is. They have already trained on the whole internet, humanity hasn't produced more online activity, code, papers or books to train on yet. Specialized small local open weight models are catching up, the difference is not that large anymore.
I think the potential for AI coding assistants is huge and very interesting, but I remain skeptical we will reach a level where we can start using them for real anytime soon, unless we see architectural improvements, and they only come about every 5 years or so.