[Vuejs]-Vuetify treeshaking not working with webpack

I might have found the webpack config responsible for this. But i have no idea why it does what it does.
Any idea ?

In webpack.prod.js :

optimization: {
    splitChunks: { // Extract script from vendors in a separate file
        cacheGroups: {
            default: false,
            vendor: {
                test: /[\\/]node_modules[\\/]/,
                name: 'vendor',
                chunks: 'all',
            }
        }
    },
},