Of course you can't un-invent something; that's not the point. The point is that if people want to bequeath a liveable (in reasonable comfort, by significant numbers of our species) planet to future generations, then we have no choice but to stop (to a very large extent) doing some things that some people are used to. (By the way, the majority of the world's population aren't "used to" flying - the majority of people never have flown anywhere and never will.) A very large proportion of flying is undertaken by a global elite of frequent flyers; their selfishness is part of the reason why our ecosystem is getting trashed.
Even the most frequent flyers are responsible for only a tiny fraction of the overall CO2 release. By far the most damaging factor is energy generation (especially coal), and it's subsequent use. Then not too far behind is the simply staggering 30-40% of food waste that industrialised nations generate, as well as the incredible amount of junk (food & other goods) we consume. And its not just the global elite that are consuming, we all are. Trying to label the "elite's" flying patterns is almost as bad as generalising the political alignment of eco-campaigners. I've no love of the one percenters, but they are not the problem here.
The problem I have with flight-shaming, and indeed many other forms of eco-campaigning is that it largely ignores the real problems, primarily because they are large & complex, but also for some are simply not sexy enough. Shouting at people on social media about their overseas holidays whilst proclaiming they will no longer fly is a frankly lazy, if popular bandwagon to jump on and virtue signal from. Trying to rally support for people to consume and waste less is far more difficult, and something those very same campaigners are probably just as guilty at. And there is the long & difficult road of campaigning governments for long term change, something many campaigners get bored of very quickly.
Sadly the real solutions are not quick wins, and reversing the effects of hundreds of years of industrial & agricultural damage (yes it started many centuries before the Industrial Revolution) that mankind has afflicted on the planet is going to take, well frankly hundreds of years. So its time to face the reality that prescriptive targets set for 2030/2040/2050 will only tickle the surface of the problem, and that we need to stop tinkering around the edges in an effort to feel better about ourselves, & actually get the real work done.