Works on My Machine (I mean with Gatsby build)

index.without.suspense.js

import React, { useState, useEffect } from "react"
import { graphql, useStaticQuery } from "gatsby"
import Layout from "../components/Layout"

const importBlock = blockName =>
  import(`../components/blocks/${blockName}/index.js`).then(
    component => component.default
  )

export default () => {
  const [components, setComponents] = useState([])

  const { allDirectory } = useStaticQuery(graphql`
    {
      allDirectory(filter: { relativePath: { ne: "" } }) {
        edges {
          node {
            relativePath
            id
          }
        }
      }
    }
  `)

  useEffect(() => {
    function loadComponents() {
      allDirectory.edges.map(async ({ node }) => {
        const component = await importBlock(node.relativePath)
        setComponents(loadedComponents => loadedComponents.concat(component))
      })
    }

    loadComponents()
  }, [allDirectory])

  return (
    <Layout>
      {components.map(Component => (
        <Component key={Component} />
      ))}
    </Layout>
  )
}