Good enough, if you want it to be. And who's to argue that, after 300 movies in the last five years, the 'Marvel Cinematic Universe' hasn't become a kind of alternate reality, a story of such detail and such (financial) magnitude that it has acquired a weight of such significance as to actually matter? And indeed, if you want it to matter, then yes, Captain America: Civil War does matter, I'm sure. It's good enough. But it doesn't matter to me. Every time I sense a new development occurring in the sphere of superhero movies, I wonder if we've finally reached the zenith, or the nadir, of these movies, like they surely can't progress, or regress, further. And yet they surely can, and always do. Civil War feels like a turning point to me - no longer content with adequate filmmaking (at best), Marvel must now matter. And they're going full force, but with dreary insularity - not commenting upon the world outside, but upon the world within, their alternate reality; it's not for nothing that this is now known as a 'universe'. The characters engage in pithy, pointless, quasi-political discussions about issues that they don't understand, and that bear little-to-no relevance to the real lives of us viewers. It's not self-referential, it's self-obsessed, and ridiculously portentous; thus, its success is predicated upon those viewers subscribing to the reality of this fabricated universe, and deciding that, if it matters to Captain America, it matters to me too! Civil War seeks respect in its unintellectual intellectualism, though the politicking is merely a sideshow for the obligatory mega-scale mayhem. It'll draw such respect from people inclined to care about the micro-details within this sorry subgenre, in the same way that some people consider adding chocolate chips to their vanilla ice-cream a radical, exciting departure. There are other flavours out there, people! Captain America: Civil War is vanilla ice-cream, just with added chocolate chips, and it's not good enough for me*.
* Vanilla is actually my favourite flavour, but you know what I mean.