I think terminology like this is often pedantry for pedantrys sake. It's not at all clear to me that it actually adds anything of value to the language in this case, so it's perfectly reasonable for people to stop making the distinction

Yeah, but not for bulk materials like this. It was touted as a super-strong material when it first hit the news, along with all it's other properties, but that's failed to materialise yet because we've had trouble making anything larger than flakes of it.

There's no way they've been consistently guarded for all that time. People have been nicking masonry from them, I'm certain they could get lightweight valuables in and out as well

After 4 or 5 thousand years? I don't. The tombs which get discovered untouched tend to be dug into cliffsides or buried, as far as I understand it. They only survived because people forgot where they were.

Difficult to misplace a pyramid