Because you’re looking for image quality and a good scan I think a photography sub would be more helpful. You might be able to find a local photographer willing to do the heavy lifting on this one.
Data Hoarder
We are digital librarians. Among us are represented the various reasons to keep data -- legal requirements, competitive requirements, uncertainty of permanence of cloud services, distaste for transmitting your data externally (e.g. government or corporate espionage), cultural and familial archivists, internet collapse preppers, and people who do it themselves so they're sure it's done right. Everyone has their reasons for curating the data they have decided to keep (either forever or For A Damn Long Time (tm) ). Along the way we have sought out like-minded individuals to exchange strategies, war stories, and cautionary tales of failures.
I use Adobe Lightroom Classic for all my pictures. There's an auto improve command that I always use to start edit my pics, you could use something like that, but I'm not sure how it behave with colors (with normal digital pictures it usually set exposition, litghs and shades). You can install the trial version and be able to edit and export all the picture you want!
This is a topic that fairly frequently comes up on r/analog (I would know, I started a similar project several months ago and got great advice from over there). You might have more luck asking there.
I agree.
I’m in the process of scanning some of my grandpa’s slides that I found after my mom died. Some of them are over 70 years old. I’m not just trying to digitize and store everything. Some of these slides haven’t been seen in many decades, so I’m taking a lot of time touching up and color correcting every one. I’ll probably never finish the project, but it’s fun to send my dad pictures of him as a baby that he’s never seen.
Like u/mc_louis said, Lightroom is good way to do a lot of the color and lighting edits. I also believe you can copy and paste edits across several similarly exposed images, which would cut down on time. I have Lightroom with my Photoshop subscription and it’s like $10 per month.
I don't think this post belongs here.
Irfanview
You could try Vuescan for free and see if you like it better.
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.
Damselfly?