People don't always have the resources to conduct massive "proper" studies. We live in the real world, and have to settle for what studies people can conduct.
Not saying we should take such studies as the "gospel truth" ... but if you ignore them and only consider "proper" studies, you'll be waiting a very long time to learn anything new.
You are saying the companies that are planning to build structures the size of Manhattan, while claiming multiple trillions TAM, and eventual apotheosis, along with the consumers of these models can't scrape together enough coins to fund a study with a decent statistical power?
We have to settle for 'crumbs'?
Why would you say this like it is true?
These studies are often conducted by the AI companies them selves (in this case, an institute that receives funding from AI companies), if they were interested in the truth (which they obviously are not) and not propaganda (which they obviously are) they would fund the necessary research. AI companies have plenty of money and can well afford to do this properly.
Other then AI companies, a more realistic option are state funded universities (particularly in Europe and east Asia) which have consumer protection agencies who’s purpose is to protect their residents from corporate greed, and as such should fund, commission, or even conduct such studies. They also have enough money to do this properly.
If there is enough money for propaganda, there should also be enough money for the truth.