Long file names instead of IMG_1234.jpg in Finder

Below your post is "macOS 10.13" shown, but you screenshot suggest macOS 10.15 Catalina.

It is a new feature in Photos 5 on Catalina. Photos is renaming all original files on import. You cannot prevent it.

I would back up all original image files you are importing to photos on an external volume, to preserve the original image files. Photos will recreate the original filenames, when you export thephotos with FIle > Export > Export unmodified original".

See: How Photos 5.0 on Catalina Manages original Files and Filenames

As you obviously don't want to use Photos.app, perhaps you would consider simplifying your work flow by using Image Capture (in the Applications Folder) to get the images from your phone to your folder system.

robertnorgren wrote:

Thank you. This retains the file names but it creates live photos as a jpeg and a separate quicktime movie. Hmm... I wonder if there's another way or if Im stuck with the Photos app.

This is normal. A Live Photo is a pair of a video clip and a high resolution still frame. You need the Photos.app to see this pair as a Live Photo. Keep both exported files together in the same folder. If you reimport them to Photos they will appear again as a Live Photo. If you want to use Live Photos in other application, use either the video component for the animation or the still frame as the high resolution photo.