Being able to put a PC together doesn't mean you understand computers. If I ask you to make me a computer that runs a wristwatch, you'll likely be lost unless you have very specialized understanding.
I think we actually all know what "poorly understood" means. There's no need to play tedious semantic games.
The semantic game occurred when someone was equivocating "LLMs are poorly understood" with "brains are poorly understood", which are worlds apart in the extent to which they are "not understood".
“equivocating” is not the word you meant to use here. Probably “equating” I suspect. But yes, I stand behind my claim and I deny that it’s a semantic game. The two areas are not identical in human understanding but they’re on the same order.