Two files of a million digits, statistically identical, and yet one compresses to three lines and the other never will. Chasing that gap splits the idea of 'compressible' into two very different things — and leads to a strange wall: you can always prove a thing can be compressed, but never that it can't.
I mean, yeah two d6 are random but adding them doesn’t give you an even 1-12. It’s a bit more obvious with the d6’s though.