T'Challa in Black Panther is the least interesting out of its 10-12 most prominent characters and I wouldn't say it's really "about" its themes in any meaningful way. Just cause it brings them up doesn't mean it's deep all of a sudden. If anything it works best at its most visceral, like in the one-on-one combat scenes.
Regardless both BP and IW are barely above average and I'm not looking forward to them being non-stop worshipped here till, well, their 2019 analogues in Captain Marvel and A4.