> You refusing to write open source will do nothing to slow the development of AI models - there's plenty of other training data in the world.

There's also plenty of other open source contributors in the world.

> It will however reduce the positive impact your open source contributions have on the world to 0.

And it will reduce your negative impact through helping to train AI models to 0.

The value of your open source contributions to the ecosystem is roughly proportional to the value they provide to LLM makers as training data. Any argument you could make that one is negligible would also apply to the other, and vice versa.