"You" this particular function might not know how to handle it, but it's possible that some other part of the program does.
To run with your example, I could imagine handling a missing storage device in lots of different ways, including a) Retry the operation b) Alert the user and block until a device (re)appears c) Switch to an alternative storage location d) Replace the to-be-read-in values with some sensible defaults.
It seems to me that it would be easier to write this logic once and place it in an exception handler than it would be to wrap every I/O operation in a thicket of if/else clauses.
To run with your example, I could imagine handling a missing storage device in lots of different ways, including a) Retry the operation b) Alert the user and block until a device (re)appears c) Switch to an alternative storage location d) Replace the to-be-read-in values with some sensible defaults.
It seems to me that it would be easier to write this logic once and place it in an exception handler than it would be to wrap every I/O operation in a thicket of if/else clauses.