Let me reframe it. Among these trillions of people, there will be many who are 99% similar to you. Wouldn't you want that version of yourself to live a great life?
Sure! It's just not actually reasonably possible to predict what will lead to that outcome, whereas I can sorta (badly) predict what will make me happy tomorrow, my wife happy next week, and what will best improve conditions for my current fellow citizens of the world.
You can certainly rationalize anything, but I fail to see what help that is to us.
"The great subverter of Pyrrhonism [radical skepticism] is action, and employment, and the occupations of common life. [...] I dine, I play a game of back-gammon, I converse, and am merry with my friends; and when after three or four hour's amusement, I wou'd return to these speculations, they appear so cold, and strain'd, and ridiculous, that I cannot find in my heart to enter into them any farther."
Yes, exponential growth gets quite large quite fast. Think about how a $300 graphics card today competes against one from 15 years ago. They're orders of magnitude faster, more memory, etc.
Easily imaginable: every country with big enough nuclear arsenal could be viewed as a country holding the fate of the world in its hands.
But since there can be multiple such countries at the same time and since no one has stopped developing arms/tech even further - I wouldn't call it a paradox when one nuclear country feels threatened by another group of both nuclear and non-nuclear countries coming closer and closer to its borders.
The difference between a rational person and a narcissist is this: one recognizes the sufficiency of world-destroying power, the other will always demand more, regardless of the absurdity.
