Norm,
Sorry this has happened, I to have been forced into Photos, kicking and screaming, but my last computer that would support iPhotos and Aperture died on me, and no going back on OSX when you buy new hardware. I'm totally sympathetic, I've not been using iCloud, my images and Photos Library are on an external hard drive, backed up to separate external hard drive using Time Machine. So, my set up may look different than what you have.
Some thoughts, Hopefully helpful, Maybe you have already looked/tried this:
The Photos app is really just a viewer/editor for a database, the actual files and originals should be buried/hidden in a file that Apple does not want you messing with, as it can corrupt the DB if you start moving things around.
In Photos Preferences/General, there is a link to the "Library Location" and a button "Show in Finder" if you click that it takes you to the your actual Photos DB file.
You need to Right-Click or Control-Click on that file to get a dialog that lets you "Show Package Contents" This then opens up a standard drive menu, which you can see a lot of files and folders. One folder is called "Originals" it has many sub folders in it, and should have all your original downloaded image files in it. Unfortunately, At least in mine, they are all renamed and inscrutably organized, so it becomes a wild snipe hunt to find an individual image. It's not convenient, but at least you should still have your original images locally.
iPhoto had a method to right click on an image in it, and go to the original, in the file directory, I'm not finding an equal in Photos, but Photos still has a way to export the original (File->Export->Export Unmodified Original), which loses any edits you made to it, but seems to be the original RAW file, with EXIF intact, when I do it. Perhaps this will work to get back to your RAW files with correct EXIF. It does lose all your edits to an image though.
I'm frustrated with many things in Photos, I don't care for the editing tools interface, I don't like that it only reports the FF converted focal lengths, in the image info; too much iOS influence in it, but like you, I feel like I paid for it with the hardware, and don't use enough bells and whistles of the Adobe products to justify their subscription, and associated annoyance.
Hoping this is somewhat useful to you, I know it's not the solution you need or are looking for.
Last edited by K-Three; 02-05-2023 at 05:42 PM.