I googled: why is windows 11 slow
https://tinyurl.com/nhe7k3kp
Many many posts with the same complaint.
For future copying and moving files use: TeraCopy
You start the copy or move process and it does not stop like Windows explorer does constantly.
https://www.codesector.com/teracopy
To replace Windows File Explorer use XYplorer. I have used it since 2007.
You can have tabbed folders. You can change the look quite a bit. I added 5 extra buttons on the toolbar that I use to click to view thumbnails, list, details, preview pane, navigation panel. You can move the buttons around in the order you want and also change the size of the thumbnails displayed. Check a box Tools> Configuration to make it the default file manager.
https://www.xyplorer.com