FileSystemWatcher Not recognizing change in directory

So I am trying to create a console application that will watch a directory and when a folder is dropped into the directory it will optimize the files inside of the folder. The optimization part is working. I am currently concerned with the fact that once I run the program with the FileSystemWatcher it never recognizes the change. Is the class only focusing on the root directory and not going any deeper?

I also saw on Microsoft's website that the way to watch for a file that has been copy pasted or moved into the directory is by using FileSystemWatcher.Renamed instead of .Changed which is what I was having an issue with before.

using System;
using System.ComponentModel;
using System.Diagnostics;
using System.IO;
using System.Linq;
using System.Net.Mime;
using System.Runtime.CompilerServices;
using System.Threading;
using pdftron;
using pdftron.Common;
using pdftron.Filters;
using pdftron.SDF;
using pdftron.PDF;
using OptimizerTestCS;

namespace PDFNetSamples
{

    class Class1
    {


        private static pdftron.PDFNetLoader pdfNetLoader = pdftron.PDFNetLoader.Instance();

        public static void Optimize()
        {
            Thread.Sleep(1000);
                PDFNet.Initialize();

                string input_Path = @"C:\Users\user\Desktop\testinp\";
                string output_Path = @"C:\Users\user\Desktop\output\";
                string[] files = Directory.GetFiles(input_Path, "*.pdf", SearchOption.AllDirectories);

                foreach (string file in files)
                {
                    string fileName = Path.GetFileName(file);
                    Console.WriteLine($"Optimizing {fileName}");
                    string sub = file.Substring(35, 7);
                    CreateFolder(output_Path + sub);

                    try
                    {
                        using (PDFDoc doc = new PDFDoc(file))
                        {
                            doc.InitSecurityHandler();
                            Optimizer.Optimize(doc);
                            doc.Save(output_Path + sub + fileName, SDFDoc.SaveOptions.e_linearized);
                            Console.WriteLine("Done..\n");
                        }
                    }
                    catch (PDFNetException e)
                    {
                        Console.WriteLine(e.Message);
                    }
                }
        }

        private static void Run()
        {
            string[] args = Environment.GetCommandLineArgs();

            if (args.Length != 2)
            {
                Thread.Sleep(3000);
                Console.WriteLine("Usage: Watcher.exe (directory)");
                return;
            }

            using (FileSystemWatcher watcher = new FileSystemWatcher())
            {
                watcher.Path = @"C:\Users\user\Desktop\testinp\";

                watcher.NotifyFilter = NotifyFilters.LastAccess
                                       | NotifyFilters.LastWrite
                                       | NotifyFilters.FileName
                                       | NotifyFilters.DirectoryName;

                watcher.Filter = "*.pdf";

                watcher.Renamed += OnChanged;

                watcher.EnableRaisingEvents = true;

                Console.WriteLine("Press 'q' to quit the sample.");
                while (Console.Read() != 'q') ;
            }
        }

        private static void OnChanged(object source, FileSystemEventArgs e) =>
            Optimize();

    static void CreateFolder(string path)
        {
            Directory.CreateDirectory(path);
        }

        public static void Main(string[] args)
        {
            while (true)
            {
                Run();
            }
        }

    }
}