[There are a few mild spoilers in this. They were all either in their respective films' trailers or in their first few minutes or are frankly trivial and don't matter, so nothing major. Don't read if you don't want to risk it.]
Superman is the dullest of all superheroes. He's just too damn super, forcing the writers to come up with yet another way for a bad guy to get hold of some of the frankly implausible amounts of weaponized kryptonite that are lying around, again and again and again. The writers themselves realised this pretty fast, which is why every subsequent superhero is markedly less super and pointedly vulnerable. Until Black Panther.
The opening of Black Panther tells us about the African nation of Wakanda, built on huge deposits of that old favourite of scientifically illiterate comicbook writers, magic super metal (in this case, apparently, "vibranium", but really, who cares?), which makes absolutely any plot device possible, because it is so super it's magic. The Wakandans have built their civilization on this stuff and make their amazing tech out of it and even weave it into their clothes. This makes them an entire nation of Supermen. Which makes them dull.
For a plot to be engaging, there needs to be jeopardy. It doesn't have to be physical: in a romantic comedy, boy meets girl and they proceed to utterly fail to get together for most of the movie. We have to believe that there's a real chance that Harry and Sally won't end up together, or where's the entertainment? In disaster movies, some of the main characters die, so there's always a chance our favourite will be one of them. In a sport film, we have to think the athlete might lose — and Rocky did. In action films, we have to believe the people we're watching are in danger.
Of course, with CGI and so on, that's getting harder and harder to do. Jackie Chan does it by sticking out-takes at the end of his films, in which we get to see him fuck up and even injure himself, so we know he and his stuntmen really do the stunts we see on screen. That knowledge invests us in what we're watching. Prachya Pinkaew has taken the same approach, to great effect. Dan Bradley is a master of putting actors in the middle of insane action and pulling the audience in after them using sheer inventiveness — getting a cameraman to jump off a roof being my personal favourite of his moments. It doesn't really matter whether it's the actors or the characters in danger. It just matters that we believe in the danger.
With superheroes, this is doubly important, because they're going to spend most of the film being super. This is why Iron Man starts with Tony Stark bleeding to death. Thor starts with his hammer being taken away; Thor: Ragnarok starts with it being destroyed. Captain America starts out as a wimp. Dr Strange starts out by being crippled. Ant Man opens with Scott Lang being punched in the face and bleeding. Peter Parker gets bullied at school. The Incredibles starts with every superhero having to go into hiding from a public that hates them. It is important to establish early on that these characters are capable of being beaten and hurt.
Black Panther starts with a James-Bond-type scene in which it is made abundantly clear to us that this hero is never going to get hurt. He jumps out of a plane without a parachute, lands safely, and then ignores being shot at point-blank range with a machine-gun. In case we thought it was only him who can do this stuff because we hadn't paid enough attention to the introductory spiel about the magicsupermetal, his sidekick Okoye joins in. Soon enough, we see Wakandans thrown hundreds of yards through the air onto rock or tarmac, caught in explosions, etc, and shrug it all off. Wakandans can all do this. An entire nation of Supermen.
This is a real blind spot with the writers, Ryan Coogler and Joe Robert Cole. One of the things the Wakandans have invented using magicsupermetal is a universal remote control for all vehicles: chuck it onto a car or a plane or whatever, and someone back at base can do the driving using the interface of their choice. This is meant to impress you with the Wakandans' astounding technology, and it succeeds — but it also means that the driver in the car chase is never in any danger: they're not even there. Contrast that with Jason Bourne smashing his way through the Lefortovo Tunnel and limping away afterwards.
And it's not just physical jeopardy they fail to convey. Black Panther has a love interest. Is she interested in anyone else? Nope. Does she not love him back? No, she obviously does. At first, she seems to think their getting together would be a bit inconvenient. I don't think this fooled anyone.
There are precisely two points in the film in which any of the good guys are in any real danger: when Black Panther has to ritually abandon his powers for a few minutes to have a fair fight. In both cases, the person in danger is Black Panther himself, and we know he's going to be fine because the film's named after him and was preceded by a trailer for Infinity War with him in it.
I like the character. I like Chadwick Boseman and Lupita Nyong'o and the rest of the cast, especially the criminally underused Winston Duke. I just wish I could have believed for one second that everything might not work out just spiffingly for these people. But I couldn't.