Surely the answer is not to dispense with a form of travel many people enjoy, but to find ways of working with rather than against it, in a productive rather than destructive manner? There is something very OTT in the XR-type response that simply (and unrealistically) wants to see whole industries or ways of life disappear rather than trying to find viable solutions. The latter is what we have a responsibility to be doing.
The aviation industry are currently thinking they are equal to this challenge (at least, Heathrow aiport is), and only time will tell. But they are making good noises in the right direction. One is to use recycled, greener aviation fuel using technology the Germans developed during WW2 in case fossil fuels became unavailable (why we've been sitting on that ecological goldmine for over half a century beats me, but as they say, better late than never). There are other firm plans for reducing CO2 and developing more environmentally friendly systems and standards on the ground. Hopefully it will work and if so, other airports around the globe will follow suit.
I'd rather see the cruise lines developing along these lines, or being forced to comply with measures such as these, rather than disappear completely. We used to cruise pre-family, but stopped once the port-stays became many hours shorter to save on costs. For us the objective was to see many places in relative comfort and across a short space of time. When it became less about the places and more about the onboard experience (which we never cared about anyway) it lost its appeal.
But given the right circumstances, I'd still like to do a rocky mountain railroad trip and a cruise of Alaska!