score:2

Accepted answer

It has to do with the Javascript portion of Bootstrap. The CSS will work just fine with a link tag.

But React and Angular are Javascript libraries which have a lot under the hood for manipulating the DOM. If you also use something like Bootstrap or jQuery to manipulate the DOM, it probably won't play well with React or Angular since they're trying to do similar things in very different ways maybe at the same time. So DOM-related Javascript libraries need to be rewritten so they play nicely with React/Angular.

From the react-bootstrap docs:

we don't ship with any included css

All they deal with is the JS.

score:1

When you chose to work with reactjs you chose a library that updates your DOM in a cleaver and sophisticate way.
It has the virtual DOM and bunch of algorithms (like the Diffing algorithm) to determine when and how to update the DOM in the most fast and efficient and performant way.

When you combine this with another library that updates the DOM, you basically interrupt those algorithms to do their job.
Beside performance aspects, you are working against the pattern of react, you break the "component pattern".
React-Bootstrap is here to help you maintain your component pattern with their components. you just need to include the css and other resource files.
Their components doesn't do anything beside rendering HTML with proper class names that correspond to the classes that in the bootstrap's css files.
They do that in the same way all your other components do it, via props.
This way you can have a bootstrap components that play nice with your other components in a native way without breaking the pattern.

Yeah, it's easier to dump some css and js files and things just works, but it's harder to maintain, debug and scale.


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