Does React somehow speed up the page or is it just a ready-made solution in the form of a library?

Question

React

Hello!
Tell me, does react somehow speed up the site or is it just a convenient tool that will be clear to everyone who studies it?

Answer 1

React somehow speeds up the site

Compared to what?
React speeds up the development of medium-complex systems.
This is the acceleration of the developer's work first of all.

Answer 2

It does not speed up, but vice versa - if you write in pure js, then you do manual manipulations with dom, and you decide what and when will be redrawn.
The react itself calculates for each change what should be redrawn and what should not - this is the very calculation of the react and slows down.
This is very rude.