It's complicated. For one, yeah, those offsetting companies calculate very generously. E.g. I once looked a bit into this and they make arguments like "we don'

It's complicated. For one, yeah, those offsetting companies calculate very generously. E.g. I once looked a bit into this and they make arguments like "we don't consider construction of the airport, because it's already there". The calculations for the offsets are also often calculated very generously, e.g. they often use the same mechanisms as the so-called Clean Development mechanism (which is part of the european emission trading system), which is known to overcalculate savings enormously. The other thing is they offset things the cheapest way possible. That works as long as there are cheap ways to save carbon. It doesn't scale.