It's good practice to remove redundant cables and switchgear, sadly not everyone follows good practice.
The jointed alarm cables are indeed a right mess and should be enclosed in a box of some kind. As to the reason they've been joined here - either some berk chopped through them accidentally, or the alarm panel has been moved to a different location.
The metal pin is an early earth rod, usually installed when the earthing arrangement is TT.
Again, poorly installed, with no proper means of connecting the cable, and no protection from the elements. There should be an inspection pit sunk in the ground.