That if is the biggest issue. These carbon calculations require a lot of math and assumptions and uncertainty to work. In the global economy with many steps along the path from source to sink, every actor has an incentive to make things look better than they actually are. So research on the topic has found a wide variety of issues with carbon offsets and other strategies that aren’t direct reductions of in emissions. So it’s pretty likely that net zero would not actually be net zero. Reducing emissions directly is much easier to verify.

Also, millions die from air pollution every year and net zero doesn’t do anything about that.