Why does a named import increase the Package size?

It seem to me like you import React completely, and in addition you import a module from react.

Try import { Component } from 'react';

import { Component } from 'react';

Breaks the app. I don't see the advantage of using:

import React from 'react'; 

VS

import React, { Component } from 'react'

If it only saves you typing the React. part but increases your package size, it down't seem worth it.

tl;dr - development files aren't production files, and their size isn't reflective of the final product.

I think that this is a fundamental misunderstanding of your React dev environment vs your compiled final product. The create-react-app structure only has your dev files, and when it's time to move your product to production, you use

npm build

to compile those build files into a set of productions files. Those production files do not use all of those individual imports in your final build. Instead, the dev environment compiles your javascript, rendered html, and css, minifying and bundling them for you in the most efficient way possible (according to the environment's logic).