Many people type with Cangjie because that's what gets taught. Very few people know Jyutping, and even fewer type with it; most people encountering Jyutping for the first time wouldn't know how to pronounce it, largely because of the unfamiliar 'j' and 'eo'.
For day to day transliterations of names etc there's actually no standard, just some loose rules based on English pronunciation.
For day to day transliterations of names etc there's actually no standard, just some loose rules based on English pronunciation.