Simple script, is it possible?

For lot of swatches, the coloring of text characters has poor performance. That's why I find the second version of the script more interesting. It creates a separate text for each name and places it sequentially on the artboard.

/*
  Output swatches as a group of text objects, with each name colored with the swatch
  Discussion: https://community.adobe.com/t5/illustrator-discussions/simple-script-is-it-possible/td-p/13944314
  Author: Sergey Osokin, email: hi@sergosokin.ru
  Check my other scripts: https://github.com/creold
*/

//@target illustrator
app.preferences.setBooleanPreference('ShowExternalJSXWarning', false); // Fix drag and drop a .jsx file

// Main function
function main() {
  var isOnlySpot = false; // true - output spot colors, false - all swatches
  var fontSize = 8; // Pt
  var typeface = 'Arial-BoldMT';
  var isUseUppercase = true; // Convert name to uppercase
  var pads = 20; // Artboard paddings
  var distX = 4; // Horizontal distance between text
  var distY = 2; // Vertical distance between text

  if (!documents.length) {
    alert('No documents\nOpen a document and try again', 'Script error');
    return;
  }

  var doc = app.activeDocument;

  var swNames = getSwatchNames(doc, isOnlySpot);
  if (!swNames.length) {
    var msg = isOnlySpot? 'No spot colors found' : 'No process or spot colors found';
    alert(msg, 'Script error');
    return;
  }

  var allTfs = [];
  var lay = getEditableLayer(doc);
  var idx = doc.artboards.getActiveArtboardIndex();
  var abRect = doc.artboards[idx].artboardRect;
  var totalW = abRect[2] - abRect[0] - 2 * pads;
  var x = abRect[0] + pads;
  var y = abRect[1] - pads;
  var curW = 0;

  for (var i = 0, len = swNames.length; i < len; i++) {
    try {
      var tf = addText(doc, lay, swNames[i], isUseUppercase, fontSize, typeface);
      // Start a new row if total width exceeds given value
      if (curW + tf.width > totalW) {
          x = abRect[0] + pads;
          y -= tf.height + distY;
          curW = 0;
      }
      tf.position = [x, y];
      x += tf.width + distX;
      curW += tf.width + distX;
      allTfs.push(tf);
    } catch (err) {}
  }

  if (allTfs.length) groupItems(allTfs, 'Swatches Legend');
}

// Get document swatch names
function getSwatchNames(doc, isOnlySpot) {
  var arr = [];
  var swatches = doc.swatches.getSelected();
  if (!swatches.length) swatches = doc.swatches;
  for (var i = 0; i < swatches.length; i++) {
    var sw = swatches[i];
    var swColor = sw.color;
    if (/nocolor|gradient|pattern/i.test(swColor)) continue;
    if (swColor == '[SpotColor]' && swColor.spot.colorType == ColorModel.REGISTRATION) continue;
    if ((isOnlySpot && swColor == '[SpotColor]') || !isOnlySpot) arr.push(sw.name);
  }
  return arr;
}

// Get layer to create object
function getEditableLayer(doc) {
  var aLay = doc.activeLayer;
  if (aLay.visible && !aLay.locked) return aLay;
  for (var i = 0, len = doc.layers.length; i < len; i++) {
    var curLay = doc.layers[i];
    if (curLay.visible && !curLay.locked) {
      doc.activeLayer = curLay;
      return curLay;
    }
  }
  doc.layers[0].visible = true
  doc.layers[0].locked = false;
  doc.activeLayer = doc.layers[0];
  return doc.layers[0];
}

// Add colored text object with swatch name
function addText(doc, lay, str, isUseUppercase, size, typeface) {
  var tf = lay.textFrames.add();
  tf.contents = isUseUppercase ? str.toUpperCase() : str;
  tf.textRange.characterAttributes.size = size;
  try {
    tf.textRange.characterAttributes.textFont = app.textFonts.getByName(typeface);
  } catch (err) {}
  var sw = doc.swatches.getByName(str);
  tf.textRange.characterAttributes.fillColor = sw.color;
  return tf;
}

// Move items to single group
function groupItems(arr, str) {
  var grp = arr[0].layer.groupItems.add();
  grp.name = str;
  for (var i = 0, len = arr.length; i < len; i++) {
    arr[i].move(grp, ElementPlacement.INSIDE);
  }
}

// Run script
try {
  main();
} catch (err) {}

Upd 20-07-2023: You can now create a legend for selected swatches in the Swatches panel.