Because his prompt said to implement in go, not to check if an go implementation already exists.
They have been running kubernetes clusters to parse json, this is not suprising.
If they're vendoring the dependency anyway, that wouldn't matter much if they're not using features that were added since 2021.
The last release of jsonata was mid 2025, and there hasn't been new features since the last 2022 release until the latest, so it's likely those other ports are fine.
With legacy systems, at least the complexity was somewhat anticipated early in the design process (even if it was incorrect).
With automatically generated code, you get something that "works" but with a much vaguer underlying model, which makes it harder to understand when things start to go wrong.
In both cases, the real cost comes later, when you're forced to debug under pressure.
