I suggest you do a little background reading into just how difficult deep-ocean search and salvage operations actually are before passing judgement on the BEA.
I suggest you review the first phase of research .. just after SAR end
That was a big failure cause not use appropriate material (as used in phase 4)
Who take the decision for not use additional material in phase 1 (more than just pingers detection ... as they know the area was flat so easy to be scrutinized wit material as used in phase 4)
The phase 1 was triggered (location) cause ACARS (who indicated a stall)
Why phase 2 was not a remake of phase 1 with appropriate material ?