The primary strength of the federation wasn’t that it’s technologically advanced- rather that it was relatively technologically adaptable.

It was that adaptable nature that allowed Janeway et all to defeat the borg (and everybody else.)

I subscribe to the theory that the reason Q screwed around with humanity as much as he did was to push them towards being able to defeat the borg- throwing them at the cube let them see what they were up against and begin preparing before the borg were on the federation’s doorstep.

As for humanity in particular, I suspect it’s because the federation is unique in that, as seven of nine said, a collective of many voices in harmony. (More or less.)

It’s a lot of diverse worlds working together, without there being some controlling force (like the borg’s hive mind, or the Dominion’s founders,) keeping everything from flying apart.

This diversity of thought was its real strength, and it was humanity that laid the foundation for it. (Because off course we did.)