WebStyleSymbol can be used to style graphics in FeatureLayer and GraphicsLayer. This sample demonstrates how to style feature layer with 2D Web Style Symbols using UniqueValueRenderer in a map.
The code snippet below creates an array of 25 symbol names that will be used in the sample. The symbol names are well-known names from 2D Web Style Symbols. Then, it iterates through the symbol names and creates an array of value-symbol pairs as uniqueValueInfos on the UniqueValueRenderer for the feature layer.
const symbolCats = [
  "post-office",
  "atm",
  "place-of-worship",
  "park",
  "school",
  "hospital",
  "fire-station",
  "playground",
  "shopping-center",
  "campground",
  "golf-course",
  "library",
  "city-hall",
  "beach",
  "police-station",
  "subway-station",
  "train-station",
  "cemetery",
  "trail",
  "radio-tower",
  "museum",
  "airport",
  "live-music-venue",
  "sports-complex",
  "ferry",
];
rendererInfos = symbolCats.map((symCat) => {
  return {
    value: symCat,
    symbol: {
      type: "web-style",
      name: symCat,
      styleName: "Esri2DPointSymbolsStyle",
    },
    label: symCat,
  };
});More out-of-box web style symbols that can be used in 2D Maps can be found on the guide page Esri Web Style Symbols (2D).