Some airlines are offsetting carbon emissions, e.g., https://www.jetblue.com/sustainability/climate-leadership.

Aviation is also a sector where emissions are pretty much unavoidable (long distance electric flight is untenable), and offsetting emissions is the only path forward. Drawing a line and restricting aviation can't work: think of all the important connections, collaborations, business deals, etc that require aviation. One might argue they aren't needed, but such restrictions will reduce the rate of progress/innovation, which is a necessary prerequisite for climate change action. A new solar cell (for example) will not be developed in isolation.

The fact that governments don't mandate carbon offsets for aviation at this stage is appalling though. Trivial to do relative to the impact and doesn't really raise ticket prices a whole lot.