Forms sever many purposes, fighting isn't one of them per say.
The are great to familiarize yourself with a system.
The are great as a benchmark for progression.
They allow for a class environment in the MA.
Many systems use them to introduce new technoques, etc, etc.
Are forms needs for fighting?
NO.
Can they even b e counter-productive to fighting?
YES.
Are forms useless?
NO.
Are forms needed?
Depends on what you use them for.
Psalms 144:1
Praise be my Lord my Rock,
He trains my hands for war, my fingers for battle !