He has a lot more power as the CEO of Facebook than "just" a retired billionaire. Which is what humans have craved since the dawn of time.
He was leading all-hands meetings by having the teams shout "Domination!"[0][1] He's always been obsessed with Roman Emperors too, particularly Augustus (though as a Romanophile myself, I relate). Kara Swisher mentions this a lot. Even in his early days he was the "alpha nerd." Dude is obsessed with power and always has been. He explicitly cultivates this image of being above it all and just wanting to connect the world, but if you watch Facebook/Zuckerberg's actions they're always about expanding power. Similarly, Augustus PR was legendary enough to found a dynasty. He never called himself an Emperor, just the "first citizen", a citizen like everyone else, and he only was the "first" one to provide peace and stability to the people.[2] He only acquires personal power at all costs for you. Also, Zuckerberg builds shadow profiles of everyone that ever browses a website that has a facebook 'Like' button on it because it and will never delete your data because he's creating a connected global utopia.
[0] https://www.wired.com/2012/05/network-effects-and-global-dom...
[1] https://www.vox.com/first-person/2018/4/11/17221344/mark-zuc...
At this point, Facebook isn't even about Facebook. Facebook is a typical giant that acquires other companies. I would argue WhatsApp has more impact on the world than Facebook. Zuckerberg can't be proud of WhatsApp though, since he didn't build it.
To me, there is clearly no higher purpose here besides power.
In any political system other than Western democracy power is essential for physical and financial safety, if you are wealthy. Power, of course, can be attractive on its own, but in a Western democracy it can also be optional. In all other political systems it's absolutely mandatory - wealthy people without power quickly cease being wealthy.
https://en.m.wikipedia.org/wiki/United_States_v._Microsoft_C....
Microsoft is largely responsible for introducing computers to everyday people. They championed a mission of “a computer on every desk and in every home” in a way no one else was. I have strong doubts that PCs as we know them today would be a thing without Microsoft’s influence. We should also not discount the timing of highly usable Windows and Microsoft software with the explosion of internet usage in the developed world.
In the 90s and early 2000s Windows/Intel introduced computers and the internet to the masses.
Edit: Microsoft’s portable and highly desirable software lead to computer hardware being a commodity and drastically lower prices. This, combined with the timing of WWW, ignited a revolution for which Facebook is just a subset of its impact.
But it is arguable that Facebook's ability to control/spread disinformation and propaganda in regards to political elections around the world is a different, but just as powerful impact.
I think once he’s no longer at the helm of one of the largest tech firms in the world, he’s lost a lot of leverage.
Not to say he isn’t still very influential, but he’s on the sidelines of business now. And being a leader in business means having a lot of power.
Some people only understand "power" in the sense of military or corporate decisions. (This is where Trump misses the big idea.) But imagine how powerful it is to be able to set the agenda, and have most of the world follow you and agree to commit resources in the direction you set.
I would say soft power generally beats hard power, due to being more efficient in terms of costs, creating more buy-in and generating less resistance.