So there's a Wakanda the world knows about, but that's Fake Wakanda. We see in both Black Panther and Infinity War that the technologically advanced real Wakanda is hidden behind a hologram. Thus the question becomes: What does the decoy Wakanda the world knows about look like, and who the hell lives there?
Wakandans, sure, but are they citizens of the actual Wakanda who either volunteered or, god forbid, were conscripted to leave technological luxury and start roughing it Amish-style just to keep up appearances? Or is it one of those things where you live super close to a really cool metropolitan area, and when your friends ask, "Oh, nice. You live in Chicago?" you have to sigh and say, "Well, actually, I live in Clarendon Hills."
Are they able to drop by the real country when they need, say, life-saving surgery? What can be borrowed/used from their impossibly wealthy kin without giving away the truth? If they get invaded, does Real Wakanda just stand by? How in the world have 100 percent of the people who've ever lived in the decoy third-world country never spilled the beans about Real Wakanda through all of their interactions with travelers, neighbors, aid workers, etc? Unless, of course, they themselves were kept in the dark -- which must have pissed them off royally when they learned the truth.