He brings up a good point. She’s such a straight forward and honest person because of background and how privileged she is. That’s probably why she doesn’t have his street smarts and is so naive- he had to struggle so that’s why he’s fine with the bare minimum and just surviving.
His inner musings about her upbringing enabling her to be so honest/open remind me of that quote from Parasite about “being nice because you’re rich” (paraphrased). Depressing but accurate.