There's a huge amount of unproven (and possibly unprovable) assumption in that statement. There's no evidence the universe is actually continuous rather than discrete at Plank scales. No evidence in either direction, so far as I know. And given the nature of physics at Plank scales, it might be impossible to devise an experiment which could distinguish between them.

But if that's the case, it would mean it's not wrong (and not right, either) to declare that the universe is discrete, meaning all measure are in fact rational numbers.

As we're talking about design, therefore human perception, we just need to know how the resulting figure is sampled and interpreted by the human eye and mind. If you can't tell dots close together aren't continous, but discreet - then for the purpose of this discussion they are not discreet...

Discrete and continuous are not necessarily mutually exclusive. You can have discrete processes that exhibit continuous behavior. It's really important that you have clear definitions and well-described models when using these general kinds of terms.

See also Vi Hart's "Doodling in Math: Spirals, Fibonacci, and Being a Plant", starting at https://www.youtube.com/watch?v=ahXIMUkSXX0 It covers how the Fibonacci is seen in more places than it actually exists, which is closely related to the golden ratio. (This point is made at the end of part 2 and part 3 is all about it.)