MoveOldScreenshots.ps1

$Dirs =
  "E:\Pictures\Screenshots",
  "E:\Pictures\Steam Screenshots",
  "E:\Videos\Recordings\GeForce Experience\Autodesk Flow Design",
  "E:\Videos\Recordings\GeForce Experience\Autodesk Flow Design\FFBatch",
  "E:\Videos\Recordings\GeForce Experience\Genshin Impact",
  "E:\Videos\Recordings\GeForce Experience\Genshin Impact\FFBatch",
  "E:\Pictures\bh3rd",
  "E:\Pictures\Genshin Impact Screenshots"
$TargetSubDir = "old"
$Age = 14 # days

ForEach ($Dir in $Dirs) {
  Write-Output "Directory: $Dir"
  Write-Output "Target directory: $($Dir)\$TargetSubDir"

  $TargetSubDirIsCont = Test-Path -Path "$($Dir)\$TargetSubDir" -PathType Container

  If (!$TargetSubDirIsCont) {
    If (Test-Path -Path "$($Dir)\$TargetSubDir" -PathType Leaf) {
      Write-Output "Target directory is somehow a generic file, deleting..."
      Remove-Item "$($Dir)\$TargetSubDir"
    }
    Write-Output "Creating target directory..."
    New-Item -Path "$($Dir)\$TargetSubDir" -ItemType Directory
  }

  $Files = Get-ChildItem -Attributes !Directory+!System "$Dir"
  $FilesCount = ($Files | Measure-Object).Count
  Write-Output "Found $FilesCount generic file(s) in directory."

  If ($FilesCount -eq 0) {
    Write-Output ""
    Continue
  }

  $Count = 0
  ForEach ($File in $Files) {
    If ($File.LastWriteTime -lt (Get-Date).AddDays(-$Age).Date) {
      Write-Output "$($File.Name) is $Age day(s) old, moving..."
      Move-Item -Path $File.FullName -Destination "$($Dir)\$TargetSubDir"
      $Count++
    }
  }

  If ($Count) {
    Write-Output "Successfully moved $Count file(s) to target directory.`n"
  } Else {
    Write-Output "No files older than $Age day(s).`n"
  }
}

PowerShell script, designed to be periodically ran by Task Scheduler, to move older files on multiple directories into their respective sub-directories

Windows Explorer has rather awful performance when listing directories with hundreds of files, especially on HDD, if on custom "Sort by" setting (on my case specifically, Date / Descending)

So we just move much older files into a sub-directory to ensure Windows Explorer will mainly be sorting through tens of files or so (screenshots directories tend to get filled quickly)