In Chinese numerological tradition, 8's luck comes from sound rather than calculation: spoken aloud, "eight" closely resembles the word for prosperity or wealth in both Mandarin and Cantonese. That phonetic coincidence has made 8 one of the most sought-after numbers in contexts from phone numbers to real estate addresses across Chinese-speaking communities.
Western digit-reduction numerology arrives at a favorable view of 8 independently, through its own symbolic system — 8 is traditionally tied to ambition, authority, and material achievement there too, though for entirely different reasons than the Chinese tradition.