Well, the key thing is that many of them don't expect to live longer than 20 years, which means its strongly in their self interest to instead grab as much power, money and influence NOW no matter the cost.
It's not an understatement to say a lot of the ultra wealthy almost belong to a cult of nihilism either. We've ceded power to people who only care about things in the immediate future and the end result is disasterous.
But even more worrying than their average age are things like the fact that a not-insignificant number of these people are literally Christian Zionist fanatics whose unwavering support for Israeli-involved conflict is fueled by their insane belief that this conflict will bring about the biblical return of Jesus and the Rapture.
Hard to get someone to care that climate change might make the Earth uninhabitable in a couple of decades when they believe they are helping to usher in the literal End Times in a couple of years.
Trump is an absolute disaster but he's ultimately just predictably transactional and driven by boring old garden variety greed. The shadow he casts now is in some ways obscuring the fact that even when he's gone, a lot of people with a lot of power in the US government are religious fundamentalist lunatics.
This is hyperbole, the Earth will be habitable for a very long time no matter what humans do. Using fear like that is the type of thing that ultimately hurts your cause. For example people who grew up hearing about how the ice caps were going to melt by 2020 and that Los Angeles would be underwater become more skeptical when they grow up and see that none of those scary predictions came to pass.
If you want to be taken seriously it is probably a good idea to dial back the “end is nigh” language.
Also suggesting solutions like banning meat, forcing people to buy solar panels (like in California), or instating regressive taxes that hurt poor people the most (California just added yet another tax on gasoline) are just not going to work.
Normal people see WEF talks about eating bugs and banning meat and think your cause is insane and dangerous. Honestly, they are mostly correct.