How to flourish and excel in a scheme

[Bisco]

I've been out of the aquarium game for around 4 years, my last setup was a saltwater tank, so this is a new venture for me - a planted tank. I've chosen a Fluval Spec 19 and I'm excited to get started. I've read that CO2 can be beneficial, but then I dug deeper and it seems a lot of people think it's not necessary for a low-tech planted tank. In fact, some folks say it could do more harm than good and even kill off certain plants. Is it worth skipping the CO2 altogether?