What is a noun to describe the "never gets old"-ness of an object?

Question

I want to say that a particular painting never gets old because you notice something new each time you look at it. What is a noun to describe this quality? An example sentence would be:

"Due to the xxxx of the painting, you see something new each time you look at it."

An example to the opposite of this word would be a pop song that you get bored of after a few listens. Compound words are fine as long as they are nouns. The answers to this question come close to what I'm looking for but don't fit exactly since in my situation it's not the object that changes but it's so complex that your perception of it is different each time.

Answer 1

Timeless
adjective (NOT CHANGING)

Something that is timeless does not change as the years go past:

• The city has a timeless quality as if it had existed forever.

Cambridge Dictionary

Or

Timelessness
noun

the quality of not changing as the years go past, or as fashion changes:

• She obviously chose these tracks for their timelessness, their ability to transcend generations.
• The figure in the painting looked out at the world with a serene timelessness.

Cambridge Dictionary

Answer 2

The adjective fresh is often used of art that rewards you with some new insight whenever you return to it. So you could use freshness as the noun form. But I should add that the "due to its X" construction is rather stale. It would be fresher to say

The painting is always fresh; you see something new each time you look at it.

Answer 3

I think depth would work:

Due to the depth of the painting, you see something new each time you look at it.

From the OED:

depth noun
II. The quality of being deep.
II.ii. Figurative uses.
II.ii.9. Greatness of extent or degree; intensity, profundity, comprehensiveness.
_{Source: Oxford English Dictionary (login required)}

(Depth’s vacuous pop-song opposite would be shallowness.)