We're talking about hours of study leading to a long-term hundreds of hours of time saved.
Nothing prevents you from still writing entire Babel and Webpack configs by hand if you want to, but it shouldn't be a prerequisite for actually using React (or any other framework).
The problem is there is a huge gap between a development react application and a production react application that is served to users with best security/operational processes. The own creators of CRA do not recommend it be used in production and isn't that the goal for most react developers, to put apps into production?
> No Configuration Required: You don't need to configure anything. A reasonably good configuration of both development and production builds is handled for you so you can focus on writing code.
Nowhere in the docs do I see phrases like "don't use this in production".
As for the math analogy: I'd say the difference is that many calc concepts do require understanding of algebra to grasp and use, whereas the only thing about React that _sorta_ implies knowledge of Babel is the JSX transform, which isn't a hard requirement to use React but is certainly the common preferred approach.
Again, I'm not at all saying that people _shouldn't_ learn how to set up build tool configs. I agree that's valuable knowledge to have. I'm just saying it shouldn't be a hard blocker for using React, and that React tutorials shouldn't have to spend half their time teaching unrelated build tools instead of React itself.
* spend less time debugging dependencies across version changes
* reduce bundle sizes
* create a better CI/CD pipeline
* reduce unnecessary dependencies
* fork/fix/create your own plug-ins and other tools
* self-hosting npm to avoid production/dev outages
* easily learn new tools because you understand the underlying systems/alternatives