This sample shows how to change size and density of points in a PointCloudLayer. Each PointCloudLayer renderer has two properties: pointSizeAlgorithm and pointsPerInch. Setting these will adjust the size and the density of the points.
const pointCloudRGBRenderer = { type: "point-cloud-rgb", // autocasts as new PointCloudRGBRenderer() field: "RGB", pointSizeAlgorithm: { type: "fixed-size", useRealWorldSymbolSizes: false, size: 10, }, pointsPerInch: 15, };