In Oxford Learner's Dictionary, under apparent, it says that
apparent 2: [usually before noun] that seems to be real or true but may not be
• Their affluence is more apparent than real. (= they are not as rich as they seem to be)
But I don't know the meaning of the phrase "more apparent than real".
I can totally see where you are getting confused. 'Apparent' is not a quality which 'real' would possess. The sentence is not trying to say something like "it's more yellow than a banana", but rather something like "it tastes more like beef than chicken".
In conclusion, the sentence means that "They look rich on the outside, but they are not really that rich".
This means while it seems to be real, it is not. It is just something people "see" or "perceive" as true.
It means that while something appears to be real, it MAY or MAY NOT be real.
TFD 1. Readily seen; visible: The animal's markings were immediately apparent. 2. Readily understood; clear or obvious: The error was apparent to everyone in the audience. 3. Appearing as such but not necessarily so; seeming: an apparent advantage.
Synonyms: apparent, clear, clear-cut, distinct, evident, manifest, obvious, patent, plain These adjectives mean readily seen, perceived, or understood: angry for no apparent reason; a clear danger; clear-cut evidence of tampering; a distinct air of hostility; worry that was evident in his features; manifest pleasure; obvious errors; patent advantages; making my meaning plain.
Usage Note: Apparent is related to appear, and when something appears to have a property it may or may not have that property in reality. The adjective apparent can indicate either possibility, as in The effects of the drought are apparent to anyone who sees the parched fields (that is, how they appear is how they are) and His virtues are only apparent (that is, how they appear is not how they are). Some style guides maintain that apparent should not be used before a noun to mean "appearing to be such but not necessarily so," as in The victim suffered an apparent heart attack, because a heart attack that is only "apparent" is not a heart attack at all. But in practice all readers will understand that an apparent heart attack means "something that appears to have been a heart attack, whether or not it was one."
