Without saying that they’re wrong, I will point out a couple of interesting things:
1. We all know how to read. That was a privilege for much of the past, and would be in our favor.
2. We all know fantastic things about the cosmos, physics, matter, electricity, chemicals and mathematics that were incredibly arcane to our forebearers. They all seem commonplace now, of course, which is why we discount them.
3. Even with a modest understanding of warfare, we have the opportunity to be quite effective in updating the tactics and strategy of our government-of-choice.
4. A modest amount of cryptological sophistication goes an incredibly long way. One-Time Pads, anyone?
5. Our understanding of health and human anatomy is tremendously advanced, even at a casual level. Germs, viruses, exercise, healthy eating, vaccines – you can explain all of this to people of the past, and improve their lives immeasurably.
6. You know which composers and authors and artists are successful, and you can arbitrage that knowledge for certain kinds of work.
Of course there’s a lot of “ifs” in this – if you meet the right people, if you have some early successes, you’ll go on to tremendous later success.
But the idea that someone who is educated and literate ending up doing manual labor seems wrong to me. Anyone who could read well automatically had a huge leg up for most of history.