Live support systems are an essential and necessary part of a Martian settlement, since the natural Martian environment does not allow human beings to survive.
The life support system on the ISS is optimized to low weight. It must be fuelled with large amounts of energy and it requires a constant replenishment with consumables.
On Mars we will not be able to maintain a life support system that needs consumables. The alternative is a near-natural carbon cycle with the growing of food and producing oxygen at the same time.