Based on my experience, infini and radiofrequency microneedling is a new treatment. I usually don't believe in a treatment until its been out in the market for at least 5 years or more. What I do know is that the co2 laser does work but you need to do some special things with the laser and use the laser in a new way. Treating the deeper layers is essential. I would find a doctor that can do all of these things with one treatment and not have to get multiple treatments to get a significant result.
CO2 is a laser. It can go a depth of about 1.5mm. It is the most powerful skin laser available. It has the highest risks of all lasers too. In your skin type, hyperpigmentation is a moderate risk. I would only do fractional CO2 with your skin and then you would probably need 2 or 3. The Infini is RF technology and can go up to 3.5mm depth although you don't need to go that deep for this problem. It has much less risk and less downtime. With CO2, it is about a week of staying in the house with wound care. Infini patients can work out the next day in most cases. I have found results to be better with Infini than with CO2.