100% behind you regarding the devastating impact of capitalism on society and ecology.
However, the mass extinction began at the end of the Pleistocene with the megafauna. From the Paleolithic to the Middle Ages, humans never behaved sustainably.
Now that we have the scientific method and we are able to predict accurately the consequences of our actions, I want to believe that our spieces is able to change. Currently, capitalism is one of the main force against improvement.
If your question is genuine: Kings in European constitutional monarchies (or at least in Belgium) play a political part outside of the political circus of constant posturing.
First, they help to broker deals between parties elected by the people. In Belgium we have the awesome proportional representation, meaning that we escape the drawbacks of first-past-the-post. But we have a shitton of parties that need to negociate and compromise. The king is the showrunner but only elected officials are in power in the end.
Second, they perform diplomatic missions. These missions rely on personal bonds maintained over decades are more stable than for a president that can change every few years. The phone calls of the King allowed Belgium to obtain needed gear during the covid pandemic. We can also see how quickly relations can suffer when a bad president is in office. A King means stability.
Finally, the King must know his place. If he steps out of line and expresses the tiniest personal political opinion, he’s sidelined real quick. That happened in Belgium when the King refused to sign legalization of abortion. The parliament declared him unable to reign and the law was passed anyway.
That’s neat! We should have this for European brands as well.
Well, my hope is that humanity was so destructive out of ignorance. I hope that science and education, or in general the knowledge of how we impact the world and the consequences, lead to wiser choices. This could be for egotistical reasons (a healthy ecosystem leads to easier life for humans), or out of respect for other life forms.