Idiom or expression request that would convey same meaning as this Persian set phrase " simple yet impossible to imitate"

Solution 1:

Deceptively simple, perhaps (i.e. not so simple as it appears to be)

Solution 2:

Matchless simplicity

Inspired by Papa Poule's answer.

Solution 3:

I can't think of an idiom, but the expression I'd use to express the concept of "simple but impossible to imitate" is:

unique in its simplicity.

The expression is used as shown Ngram and clearly refers to something impossible to imitate (unique) but simple.

Usage examples:

• The narration itself is unique in its simplicity,..... From: Handful of Clay in the Potter's Hand -

• This theme has been painted innumerable times in Christian art, but aesthetically Angelico's fresco in Florence is unique in its simplicity, ...From: Aesthetics as a Religious Factor in Eastern and Western ...