It staggers me we continue to have faith in the PLB/ELT/EPIRB. Aircraft are stuffed with them but more often than not they fail to activate or be activated.
Duty of care of the ad hoc operator is to provide flight following until destination reached. This can be done on a smart phone nowadays. An ELT signals bounces around the globe via telephone lists and may eventually start a trawl and search if the records are up to date, if the aircraft is carrying the correct complement.
A satellite tracker IS reliable .... a simple burst transmission of lat and long every 3 mins or so, not a 2 minute conversation. It works. It provides a track; if the flight stops abruptly at least you have a point within 3 minutes of where it probably is located. You can see if they turned back due to weather, it's blindingly obvious.
A flight follower would have realized where the aircraft was yesterday and reduced the uncertainty and time wasted for search and rescue crews.