We have internet and can remote easily, why do so many people travel by air still
For the purposes of chain of custody (which may be very important if this ends up being criminal investigation as some point, but also goes to the trust of the entire process), all access to the evidence, when it is not otherwise secured, must be in person, with colleagues and witnesses present, when the evidence is opened and accessed using certified equipment suitable to the task. The 787 uses two EAFRs (a combined flight data and voice recorder), with one in the forward part of the aircraft and one in the rear. One was extensively damaged, and required more extensive data retrieval work.
A leading theory by people who actually know the plane (including pilots) is that this appears to be another EgyptAir Flight 990, which was suicide by plane (with Egypt insisting publicly that their co-pilot would never do that). The preliminary report by the AAIB did not provide any evidence to contradict the suicide by plane theory (and even strengthened it a bit, much to the consternation of the pilots union). It is possible the NTSB and the AAIB will come to different conclusions.