Yeah every couple years I buy new hard drives.

I have about a dozen that are about 10-20 years old. It's getting hard to find a use for them, but so far I just use them as a 5th level backup, write once. I also destroyed a bunch that were too small.

Use internal drives with a dock and store cold. Saves the hassle of dealing with a bunch of cases and power adapters.

For fully on backup all the time use a versioned backup like time machine or a cloud service.

I'd look at products like topaz photo ai. It should do things like color correction, brightness and sharpening. I don't think it does dusts spot / scratches although that's probably on the feature list to add. You could also use a two step process with another program for dust spots.

If topaz or similar ai product doesn't do exactly what you want, I'd start scanning but wait a year or two to process as these programs are rapidly improving.