[BFay]

I think the gain that people are aiming for is "write once, run everywhere."

Especially if you're a lone developer - it's one thing to learn the intricacies of one platform (like web), but learning the ecosystems for Android, iOS (maybe you don't even own a mac to develop with), and native desktop apps... it's just too much work for one person. But if you could just write it once and have a good experience on each platform, wouldn't that be amazing? I guess that's what React Native is trying to solve, too.