This is remarkably difficult, if you think about it.
Only if one can actually see one’s destination, can one go “as the crow flies.”
You could be at the beach, looking across a bay, at your hotel; and you know that the quickest way to get to it is by drawing a mental line across the craggy rocks and water; though it’s so impracticable as to take many times longer to reach your destination, given that you’re clothed, with belongings.
Even air travel is not always as the crow flies. There can be territorial “no-fly” zones, for instance.
Railways and buses hardly ever use a straight route; they have to avoid mountains, towns, private property, perhaps.
So it gives me considerable satisfaction if I can literally, in its true sense, travel “as the crow flies.”