Ok so you have your first argument: Spanish and Portuguese surpass french in terms of global speakers... Bcs German is not surpassing french and german is not used in international communications
But numbers don't do anything about the power of language. Why? Cuz look at arab, 375M of speakers, wow incredible, but nobody care, cuz those country are poor, and the only rich country like to speak English or even french like Qatar, UAE, saudi arabia...
So, yep Spanish is way more speakers (and not by a lot actually) than French, but SA is poor, and Spain... Is Spain... So nothing to do.
France has the second-best diplomatic link in the world.
I could tell you more and more about how France is factually by stats and reports the second most used language in international, but you will just say: i don't use it or Spanish is more spoken than french that's will be all.