What You Don't Need Plugins For

Most third-party functionality you want to add to your website will follow standard JavaScript and React.js patterns for importing packages and composing UIs. These do not require a Gatsby plugin!

Some examples:

• Importing JavaScript packages that provide general functionality, such as lodash or axios
• Using React components or component libraries you want to include in your UI, such as Ant Design, Material UI, or the typeahead from your component library.
• Integrating visualization libraries, such as Highcharts or d3.

As a general rule, you may use any npm package you might use without Gatsby, with Gatsby. What plugins offer is a prepackaged integration into the core Gatsby APIs to save you time and energy, with minimal configuration. In the case of Styled Components, you could manually render the Provider component near the root of your application, or you could just use gatsby-plugin-styled-components which takes care of this step for you in addition to any other difficulties you may run into configuring Styled Components to work with server side rendering.