D3 is a lot more than just a graphing library, it's a toolset for efficiently editing the DOM and creating visualizations based on data.
If all you want is to quickly insert a generic bar graph into your app, then D3 is probably not for you, but if you want the ability to customize your visualizations from the ground up, then D3 is the industry standard.
In this tutorial, we are going to create three different simple visualizations with D3 in React.
Now while these things can be done without D3 and aren't particularly flashy, they highlight some of the basics of D3 very well. If you want to see some cool demos to get a sense of just how powerful D3 is, then check out some of the demos on the D3.js home page.