This example displays the top 10 most populous countries as a bar chart with no axes, using React hooks to manage state and effects. The code loads UN World Population Prospects 2019 data via `d3.csv`, parses the 2020 population column, and renders SVG rectangles scaled by `d3.scaleLinear` for width and `d3.scaleBand` for vertical positioning. React handles rendering updates, while D3 v5 provides data loading and scaling utilities.