> My eventual conclusion is very simple: the overall amount work that goes into developing web apps has increased compared to vanilla HTML/CSS/JS
Not true. Application complexity has increased over time for the web, that is the effect you are perceiving. React actually helps cut through that complexity like a hot knife through butter.
> Performance is abysmal,
The above response applies here as well. What performance are you talking about specifically? There are a ton of large scale, production applications that are running React ...
> and as is the case with many frameworks, you're soon reaching a point where your people spend more time (and in the end: computing resources) tricking the framework into doing what they want it to do.
React is not a framework, it is a very basic view library. There are literally only seven public API endpoints that developers use:
* componentWillMount
* componentDidMount
* componentWillReceiveProps
* shouldComponentUpdate
* componentWillUpdate
* componentDidUpdate
* componentWillUnmount
That's it, that's all you have to learn, the rest is generating markup and learning about setting properties and state within a component. The only exception that I will admit is that integrating react with d3 is awkward.
Having built large web applications before React came along, there is a very good reason why it is so popular and that is because it moves the focus from dealing with transitions between states and simply dealing with the state as if we were building the app from scratch.