Afghanistan is a large area. Lots of huge Mountains.
Lots of valleys and uncharted deserts.
Afghanistan is 251,825 sq miles.
California is only 163,696 sq miles
Iraq is 168,754 sq miles
It is conceivable that the jet can be covered up by
vegetation/soil/sand/who knows what.
They never found WMD’s in Iraq either.
-or- repainted to look like any of the thousands of airplanes in Pakistan/Afghanistan/Yemen.
How many stolen cars are recovered each year?
Try looking for a particular large house in California on Google Earth. It is nearly impossible. Too many places to look.
DO you know of any large jet or even a small jet crashing whose remains were never found? When any plane hits water, it breaks up. There are thousands of unsinkable items in a jet plane. 400 Seat Cushions for example. Unless the pilot landed the plane skillfully like that pilot did in a NY river. But then the whole plane would be floating.
The pilot was a devout Muslim. May be he landed it in ISIS territory. No one can prove it did not.
There is satellite data that proves the plane must have been within a certain broad circular arc on the earth's surface. ISIS territory does not overlap even the northern part of the arc, much less the far southern areas believed (based on secondary evidence) to be MH370's most likely final resting place.