Official translations often (1) censor a ton in both the text and the art to satisfy Western Puritanical sensibilities and (2) have drastically less cultural context than scans do --- scans often will have notes about references to myths/stories that manga are referencing or influenced by like creation myths or relevant stories/concepts from Buddhism or random bits of cultural stuff like why a character might sneeze randomly after being talked about.
I've yet to read an official translation that's as good as scanlations, and the notes are often more creatively integrated into the scans in a way that are useful when encountered whenever possible.
I still subscribe to the official translations out of some sense of moral obligation to send some money back to the creators, but scans are faster and higher quality often enough.