As a translator I have come to think of it like this- (without the need for defining what “understanding” means) the ability to translate correctly depends on the size of your context. So humans and LLMs are both on the same spectrum with different context sizes of their training set and all facts known in the universe (for a theoretical perfect human) respectively.

Doing moderately technical translations, state of the art LLMs may get it about 99% right but you find about 1 word per page where they would have needed to “zoom out” to a wider context to choose the word correctly. Often its an important word that is missed.