Of course you can't, its just a visual aid. The point is to say that if a cipher _completely_ breaks down at (some imaginable amount of data), then its probably

Of course you can't, its just a visual aid. The point is to say that if a cipher _completely_ breaks down at (some imaginable amount of data), then its probably not behaving itself too well at (some much more reasonable, but still large, amount of data). AES-CTR already starts to questionable in some respects at 2^40 encryption with the same key (nonce isn't relevant, it changes with every block anyway), which is only 128TiB. Sure that's a lot for the average joe, but one could eaisly imagine someone wanting to encrypt that much data with a single key, just go checkout /r/datahoarder if you don't believe me. And sure, good key rotation fixes that, but that's another foot-gun, and how should the average end user know if their application is using proper key rotation or not?