How does it make any sense whatsoever? Musk, Bezos, Zuck, etc already have more money than they can spend even if they were all to live a full life. Helping bring on the collapse of civilization would just reduce their power and control over us.
If you're saying that they believe it will collapse regardless of what they do, then they'd probably behave more like Gabe Newell and live their life by hopping from one yacht to another somewhere out in the ocean.