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.

Because otherwise they wouldn't have written this meaningless article and contributed to the AI hype.

Those are compatible with the 1.x syntax while the gnata is compatible with the 2.x. Also, the repos haven't seen new commits in a long time.

Last commits in those repos are 5 and 7 years ago.

Rewrites happen because nobody wants to debug someone else's half-finished mess, and "just use X" often means inheriting its quirks and gaps.