I have an iPhone 8. I recently upgraded from iOS 12.4.1 (if I remember correctly) to iOS 13.3.
The very first time I tried to scratch photos from my iPhone 8 on my MacBook Pro, it got stuck. The Apple Photos.app process used very little CPU, it used very little I / O (it should normally be at its maximum) and it was not progressing.
I quickly realized that it crashes if the "new batch" of photos contains a .MOV file that is "large enough", but that is about ONE MINUTE.
Not only should I force close, but the .MOV file is corrupted. I didn't realize it because I don't usually watch them, or not so soon. It is not very corrupt, they play in VLC, but they do not play in Photos.app.
So it will get a .MOV file, use all the disk space and produce a slightly borked .MOV file. Then usefully delete the original.
The stupidest possible solution is to put the longest videos in a separate "album", in the same way that iOS 13 added an album for screenshots (which makes me upset, they should all be "camera roll").
Another stupid workaround that works with iOS 13 but not iOS 12 is to use AirDrop for large videos. Which shows how they spend the money.
I'm curious to know if other people have this problem. The layout of the photos has changed a lot and I am not surprised.