by having proper air exchange via your ventilation system, you provide enough co2 for the plants

if you were using a closed system with no ventilation, then co2 enrichement would be necessary

if you have a ventilation system in place, then any kind of co2 enrichment is overkill, and if you dont have ventilation, i would highly recommend it over co2, because it is much cheaper to installer proper ventilation than a proper co2 system