What does Blockstack specialize in?

I’m new to this place. So, excuse the noobish question. I find open source software intriguing and I try to learn as much as possible. I’m work as a community ambassador / admin to V systems (a Sunny King project), and have a very limted technical background.

Now to the point, as I understand, Blockstack is a computing platform, a lot like other blockchains, but my understanding is very limited on this subject. I was wondering if there are certain things that Blockstack could do better (or worser) than other platforms? If so, then would a Dapp, benefit from having being built on 2 Blockchains? Each specializing on a certain aspect of the app?

edit -
And wouldn’t this require cross-blockchain functionalities like Cosmos?