“Need”, in quotes? I agree 100%. If I need food, and you offer me a cold bare hot dog, I’m eating it! If I “need” food and I say, “Thanks for the offer, but I’m looking for something better” then I didn’t really NEED food.

(Substitute “hot dog” with the “basic food product” that best fits your constitution!)
In this case, solutions existed equally for everyone in the world with a smartphone able to download and run messaging apps (for every new app that existed starting with WhatsApp). Folks outside the US needed to avoid SMS charges, so they flocked to applications that offered that. A quick free download in exchange for not paying .10 to .50 of local currency per message (depending on where it was going/coming from)? No hesitancy, reluctance or confusion.
If SMS costs in the US at the time were like the rest of the world, your hundreds of contacts would have settled on one of those other apps a long time ago, most likely WhatsApp. That wasn’t part of thought process around messaging apps in the US. While some of the first iPhone plans had something offered 200 text messages a month as a limit, unlimited texting very quickly became commonplace right along with unlimited data (where the rest of the world was only given unlimited data).
And the “American Company” remark is, as you say, some people didn’t want to use a viable solution primarily because they’re turned off by “American Tech Company A”, but then being ok with another one that kinda/sorta is in the same boat. And, for those folks in the US that don’t want to deal with this via Meta or Google, then, there’s still a “need” for them.