More and more anglers fish a bomb running freely on the line. This is much safer because if the line breaks, a hooked fish can pull free of the bomb.
However, an elasticated set-up has advantages, these being that the elastic acts as a shock absorber when playing a fish under the rod tip.
It also makes the rig self-hooking as a carp taking the bait pulls against the elastic. However, many fisheries don’t allow elasticated bombs or feeders so make sure to check the rules first!