Or it crashed in the ocean and people are making up stuff. There is a lot of wiggle room in these statements.
Where did you suppose it crashed in the Ocean...
Gulf of Thailand? It’s one of the most populated regions in the planet with very high volumes of shipping and air traffic, and 20 country’s navies can’t find a trace of it?
Indian Ocean? Turned off civilian coms, took a deliberate unscheduled turn, passed through 4 IFR waypoints... and then just routinely crashed nbd?
I’d say it almost certainly crashed, but the reported fact that the aircrew never reported an emergency is strange. Aircraft are very reliable transportation for good reasons. They have multiple redundancies that make it very hard to bring one down. If you’ve ever studied accident investigation, it usually takes a series of mistakes—not just one—to cause a mishap, and most mishaps are not deadly. What happened to this aircraft is like winning the lottery rare—crew apparently unaware or unable to report mishap, searchers unable to find wreckage in reported vicinity of mishap, etc.