I assumed they don’t do their research using random crap on “the internet”, but reliable experts, peer reviewed papers and such

Yes, that is what they claim. But I am sure you have seen how hard it is now to find something even if you know exactly what you are looking for. It's not like there are 2 libraries online for anything you need, right? You start researching about topic A and read that Dr XYZ did a study on this so you look for that study... just to find out Dr XYZ does not and has never existed.

No specific claims about topics, funding, time or anything. And again, no numbers, so hard to argue objectively.

So you want a specific number as to how many bad sources they are now forcing to discard because they turned out to be AI slop?