In case it is helpful, the UK does it differently (better?!).
It is the pilot's obligation to have a 'responsible person' follow their flight (friend, parent, office colleague). If an aircraft doesn't arrive, they're to call the police who will set SAR in motion. In practice this means no need to close flight plans (!), and more importantly, no unnecessary searching at all. None.
The ONLY time there is any effort expended is when an aircraft really is overdue/missing.
I personally think this should be the standard.
I say this as someone who has been called out in the middle of the night to 'rescue' someone who simply forgot to call in their safe landing (not in the UK).