Note that with AF447 we had a very good idea where it had sunk (from finding debris 36 hours after it was presumed crashed), and it still took two years to find

Note that with AF447 we had a very good idea where it had sunk (from finding debris 36 hours after it was presumed crashed), and it still took two years to find the wreck. MH370 is orders of magnitude harder to find, and AF447 was a huge effort.