Onedrive seems to think they are magnanimously letting me peek at their files on their servers, instead of having copies of my files backed up to the cloud. I once turned off syncing for a folder containing game save files, since Onedrive kept spamming me with emails warning about many files being deleted at once every time the game deleted old auto saves. Turning off the sync deleted my local files. Fuck Onedrive.

Pro tip: you should stay away from one drive.

You should always have THREE copies of your data!!!

I can just use one drive

This is the real fuck up moment. Almost anything else would've had better UI and settings to warn you before you even made any mistake. OneDrive has an absolutely awful user experience.

One drive? I sync my photos on at least two drives

Synch as in sync?

the original timestamp could still be in the EXIF data. on linux you could set it with "touch" (maybe automated with a script), but idk about onedrive or inferior operating systems

It's a bit complex to set up, but Syncthing can do one-way syncing. So you can have it set to upload photos from your phone to your PC. Then you can delete those photos from your phone and they'll stay on the PC.

Then you just need a good backup strategy for your PC.

Frankly, if you have the disk space, OneDrive should not be the exclusive home of your data. No cloud should. Your data should live on your physical computer hard drives, the cloud is just where it's backed up and shared to other computers.

Granted, this isn't how Microsoft wants you to think. They want you to think of OneDrive as your main hard drive, that your computer is just borrowing from. There aren't two files, there is one file in the Cloud, the computer is just mirroring it. Don't let them sucker you into thinking of file management like this, it is a trap to make you more dependent on them and their services.

In fact, you shouldn't even be thinking of OneDrive as a backup, because that's not what it's for. Microsoft even tells you this you really read there documentation on it. The only real backups are physical backups in your possession that don't require you to first phone home to a Microsoft server before you can access it. If a corporation is standing between you and accessing that data, it's not your backup, it's your data that you are letting them hold for you.

What you would do in this scenario is leave OneDrive doing it syncing, but COPY the files from the OneDrive folder to a non-OneDrive folder or to a second hard drive.