Does This Work if My Photos Are Already Organized?
Yes, and it does not have to move anything. Here is how to fix dates while keeping your folders.
Yes, and you can keep your structure completely intact.
Plenty of people already have a folder layout they like and have spent years maintaining. They do not want a tool rearranging it. They just want the dates to stop being wrong.
So renaming and re-foldering are optional. Turn both off and the app leaves every name and every folder exactly where it is, and only corrects the metadata inside the files. Your library looks identical afterwards; it just sorts properly now.
It also merges safely. Run it into a library you already have and photos that are already there are skipped rather than copied a second time, so you can add a Takeout export to an existing archive without ending up with duplicates of everything. Use the preview to confirm before it writes. The first 500 photos are free.