> But since LLMs don’t really act deterministically, I feel the need to double check their output.

I feel the same

> That’s very painful for me. At that point I’d rather just write the code once, correctly.

I use AI tools augmentatively, and it's not painful for me, perhaps slightly inconvenient. But for boiler-plate-heavy code like unit tests or easily verifiable refactors[1], adjusting AI-authored code on a per-commit basis is still faster than me writing all the code.

1. Like switching between unit-test frameworks