re the Feynman point, couldn't the same argument be said about, for eg, developers no longer manually writing machine code, relying on compilers instead? and the people maintaining those translation layers not knowing the phenomena that results in a transistor flip, trusting the engineering to do what it's said to do? I think an example of the kind of question this leads to would be "do you really understand software if you don't understand electrical engineering and microprocessor architectures?"

there's a level of obfuscation for any knowledge work where you rely on existing but incomprehensible-to-you systems that you just trust to work. are you unable to do any kind of mathematical work if you don't understand every single layer of proof that exists under-the-sun that touches your subject matter - or can you trust that some of these antecedents have been battle-tested and are functionally true for your purpose?

you could make an effective argument about the state of modern general-purpose LLMs that's founded on the idea that they are fundamentally untrustworthy and all results need to be validated but the larger categorical narrative, that the only true way to understand something is to know the logic from the most base principles, seems faulty

They are different -- higher level languages like C++ and Python surface the abstractions, making them more apparent to the human reading the code. LLMs typically hide the abstractions. You can still read the source code, sure, but even the latest models will produce a lot of repetition of utility functions and produce data structures of various shapes without commonality or reuse. This is moving in the opposite direction that machine code -> assembly -> C -> ... were heading.