This example renders a horizontal bar chart of UN population data for 2020 using React and D3 v5. It loads the CSV file with `d3.csv`, parses the population column, and stores the result in React state via the `useState` and `useEffect` hooks. The visualization uses `scaleBand` and `scaleLinear` to map countries and populations to SVG `rect` elements, with React’s declarative rendering driving the SVG output. While loading, it displays a large “Loading…” message before the chart appears.