The reason he said ‘giants’ is supposedly that it was a dig at Robert Hooke, who was famously short. Impressively, if true then he both managed to get this dig in and to be remembered for his humility as a result of it.
However the fun answer is: Voltron. For example our smartphones were built by Steve Jobs piloting a Voltron’d up giant. It has Tesla as one hand, Edison as the other, and their rivalry drives a lot of the dialogue. Von Neumann and Clerk Maxwell make up the torso, and the main villain for the first couple seasons is actually Maxwell’s Demon.
For some people, there are literal geniuses/die-hards/quacks that changed the industry/tooling/mindset.
For other people, they believe there are no 10x engineers and society as a whole is always to credit.
If anything, a giant in this case is an organization of humans who have toiled on those small improvements through many years.
That's the answer. Because they choose to use a metaphor instead of speaking literally.