>We used it, but once you start using libraries like that one or MobX, why even use React at all?

Well, you've got a point. I can realistically see some developers preferring to piece-meal their front end solution though, or build just the parts they need themselves. I like Vue, but the API seems enormous. I get that a lot of people like that about it, though.

Personally I don't think Vue's API is that big. Most of the bread and butter stuff are learned in an afternoon.

IMO the argument that React's API is really small is a fallacy since React is but a small piece in your project. You get nowhere without a router, local and global state management, transitions, etc.

The other factor to consider after the learning curve is productivity. Vue has a pragmatic nature and in my personal experience I can get the job done faster.

I think React is idealistic.

http://objectivism101.com/Glossary/Idealism_Pragmatism.shtml

I'm surprised to hear you say that Vue has a large API, because one of my reasons for adopting Vue was its small API. It allowed me to hold a mental model of the API in my head.

You can go through the entire docs in less than an hour and get down to business. I did not have this experience with Angular 1 (don't know about v2) or React.