I don't know much about the Gatsby. But here I have found this https://github.com/mui/material-ui/tree/master/examples/gatsby and https://www.gatsbyjs.com/plugins/gatsby-plugin-material-ui/
I hope it will help you to choose or not.
We use Gatsby and CRA. Can the Berry theme be used with Gatsby? Thx.
Name of Product/template: Berry