Optimizing VERY Slow PS Script - powershell

Question

I have a PS script that is taking CSV files (the largest being about 170MB) and splitting it into multiple smaller CSVs based on the ListGuid value. It is then taking each file and uploading it to a specific path in SharePoint using PnP based on the Web Guid and List Guid. This script it taking forever to run and I am having trouble finding ways to optimize it. Any help would be appreciated. Here is the script:
$PermissionsFile = Get-ChildItem -Path $downloadFilePath -Filter *.csv
foreach ($file in $PermissionsFile) {
$SiteCollectionReport = Import-Csv -Path "$downloadFilePath/$($file.Name)"
$filteredListTestFile = $SiteCollectionReport | Where-Object {$_.Type -eq "List"}
$groupedListFile = $filteredListTestFile | Select-Object Url, ListGuid -Unique
$subWebsConnection = Connect-SharePoint -WebUrl $SiteCollectionReport.Url[0] -CheckForAppCredentials
$subWebs = Get-PnPSubWebs -Recurse -IncludeRootWeb -Connection $subWebsConnection | Select-Object Url, Id
$permissionsSiteConnection = Connect-SharePoint -WebUrl "https://company.sharepoint.com/sites/edmsc/Internal" -CheckForAppCredentials
foreach ($guid in $groupedListFile) {
$webGuid
$listGuid = $guid.ListGuid
$SiteCollectionReport | Where-Object {$_.ListGuid -like $listGuid -and $_.Type -eq "List"} | Export-Csv -Path "Path\Permissions $($listGuid).csv" -NoTypeInformation
$url = $guid.Url
$siteCollectionName = $url.Split("/")[4]
if ($url.Contains(" ")) {
$url = $url.Replace(" ","%20")
}
$split = $url.substring(0, $url.LastIndexOf("/"))
if ($split.Contains("Lists")) {
$split = $split -split "Lists"
}
foreach ($web in $subWebs) {
if ($web.Url -eq $split) {
$webGuid = $web.Id
#Write-Host "Adding permissions reports for $split"
#Write-Host "List Guid $listGuid"
Write-Host "Web Guid $webGuid"
}
}
$fieldValues = #{"ObjectType"="List/ListItem"; "WebGuid"=$webGuid; "ListGuid"=$listGuid}
#$permissionsSiteWeb = Get-PnPWeb -Connection $permissionsSiteConnection
Add-PnPFile -Path "Path\Permissions $($listGuid).csv" -Folder "SiteCollectionPermissions/$siteCollectionName/$webGuid" -Values $fieldValues -Connection $permissionsSiteConnection
}
Write-Host "Deleting Permissions Files..."
Get-ChildItem -Path "Path" -Include *.csv* -File -Recurse | ForEach-Object { $_.Delete()}
}