Ok - but if a company were able to hire one million savants, you feel it should be illegal, because why?

Can you cite something in the copyright laws themselves that suggest this scale distinction?

This goes back to the original purpose of copyright, which is to serve as an economic incentive for individual creators and artists to make more art, by securing exclusive rights to use their own works commercially for a specified time. The goal is both the creation of more works, but also to protect the economic viability of artists.

This principle is quite universal and can be found in many places, including the US constitution and US (supreme) court decisions, many international jurisdictions, treaties and conventions.

But my question is about your point of scale.

I don't understand why it should be allowed for one savant to study and answer questions about one book, but wrong for a company to hire one million savants to answer questions about one million books.

And I'm asking where in the law or case law this is supported.

That's not what I said. The concern is not about "answering questions" about original works. That would probably be acceptable at any scale. It is whether the approach foreseeably results in the creation of market substitutes that compete with original works.

So then you agree with me that training itself is not a violation, it's whether the output is a violation.

Your arguments boil down to "If someone were doing a completely different thing and that's ok, then why isn't this ok?" and "It's not in the text of the law so it's definitely fine."

The one million savants are humans, not machines. Humans get more rights automatically in our world today. That's the moral reason for why your example is not the same. The legal stuff will be worked out in the courts and legislatures of every country in the next 5 years.