File transfer progress bars generally aren't worth shit, I have no idea how this is still a problem. It dates back to the early 90's, and it's still not done properly.
Almost everything to do with file transfer report it to be finished before it actually is, because it doesn't consider write back cache. So it's only the reading part that is finished, not the writing part. Meaning the transfer isn't actually finished. Never never never trust it is my motto. Personally I'd rather not have the dysfunctional progress bar, if I could have an actually accurate completion notification.

PS: I just switched back to KDE/Plasma after many years. Overall I'm pretty pleased, but also a bit puzzled about a lot of the simplifications.
like inability to disable caps lock, and the inability to change double click speed for the mouse. So now I need a startup command for the caps lock, and I needed to edit an ini file for the mouse for such simple things, that used to be accessible through settings???
But they finally added the ability to use numpad for hotkeys, which I found out, and was what made me switch back to KDE. Now I only miss the ability to use the scroll wheel on hotkeys too. To finally have similar functionality like I had 10-15 years ago with Compiz. 😜