That depends on (A) verification being very low cost and (B) being able to infer the right answer based on wrong ones.

Those aren't always true. Sometimes it takes a while to see the fatal flaw in an approach, and sometimes having a bunch of failed attempts isn't enough to make the right way obvious, and thinking is still required.

Good points. This is after all why LLMs are so much better at maths and software than the economy in general.