True, but that is plausibly covered by existing precedent: If a discovery is "obvious to one skilled in the art", it can't be patented. IANAL but this seems to me easily extensible to "if you can do it in two five-minute prompts you can't patent it".

Separately, land grabs are not necessarily economically bad. The land being grabbed gets into productive use fast, and the grabber is hardly going to get all the resulting value. Especially not when the monopoly is temporary, as with a patent.