THIS is the T'Challa that was missing not just in Infinity War but in his own damn movie lol
I chalked it up as "too much too soon" to cram all that in tho, bc even Iron Man didn't get all his fancy toys in his debut movie, so I gave it a pass for BP... but I'll be heated if we don't get these upgrades in the sequel. And now that they know how popular he is, i expect he'll get to do fancy things too in future teamup/event movies.
That's the real answer to the thread question. They didn't know BP/Wakanda would be as popular as they ended up being, and by then the script and movie was in the can. Nate Moore, the Marvel producer, said as much a couple months back when he was asked why BP didn't do nothing in the movie. He said they'd have made the Russos give BP more to do if they knew then what they know now.
So no doubt if they knew early on in the script/development that "Wakanda" as an extension of BP would be seen as this cultural phenomenon, they'd likely have done more with it too... esp since the source material itself has Wakanda as more star wars with its hordes of bugatti space ships than
just a buncha afrikans with spears..