As he is the president of the world how could he feel dissatisfied with his position’s freedoms. Well keep in mind he is president of the world, not king of the world or dictator of the world. He is clearly not the ultimate leader and he acknowledges this when he refers to his inability to go
to space, the place he says consistently the place he wants to go. He says “ubiebu”. He knows he can’t go to space, he has to be a cog the only man who he doesn’t say was a cog, the man he says is truly free is the man who died in space for his dream. It’s clear that space represents freedom, afterall the only people he wants to be, he says are truly free are the ones in space. This makes sense, space is the infinite journey of the unknown, the unknowable, Earth is the same old boring “free” world that he is trapped in.
The interpretation regarding the thesis being “everyone matters” or that all the populace are all equivalent can perhaps be seen as the obvious elucidation to draw however this conclusion abides to being short-sighted. I cannot reject that this is partially established in the story, for example the big quote “Everyone was a cog, from the president down to the lowest-paid worker.” however this does not cover that he seems to devalue his role through the story “...the powerful longing to travel in space far beyond the stars.” when his final proclamation of his role is that it is just “satisfying” not important or necessary just that it was okay. While he romanticises the dream to leave the planet. He clearly doesn’t think he is more important than the men who will advance the world forward. He was required but not the same.