Things disappear in the ocean all the time. Ships go down in well traveled water and never get found. A lot of the stuff you’re point too means nothing. The Hubble doesn’t look at earth, GPS requires a device to be pinging satellites, spy satellites can read lots of fine detail AFTER you know where to point them. 300 feet of plain in in 28 MILLION square miles worth of ocean (assuming it went down in the Indian Ocean like Inmarsat thinks) is basically invisible. Even if we drop it to the Southern Indian Ocean now you’ve “reduced” the zone to 14 million square miles.
This is reality not a TV show, mysteries don’t get solved in 42 minutes in reality. Out in reality mysteries often never get solved.