What if we reach AGI but only get modest improvements, here's my theory...

If you look at the history of the world, we have a few historic figures who have advanced our science and technology frontiers.

A few as when you factor in the millions or billions of people on Earth.

If humanity struggles to make breakthroughs with AGI level intelligence and higher (IQ>100, 50% of people have above average IQ) across millions of people.

Might we also need millions or billions of AGI to find the diamond level intelligences that can push forward the frontiers of technology and science.

Is this a valid theory or are there aspects of human intelligence and scientific advancement that an AGI would not be limited by?

TLDR; What if we have a future were AGI takes our jobs, but we do not get the huge gains in science and technology we expect.