Is there still no solution for this? I've got a similar issue. There is definitely noticeable difference, but it's not extra anything. I have minor vision issues and the text I have no problem reading (at 200% scale and 2280×1920 res, both the recommended setting), but I still can't see my images enough to know what exactly I'm opening.
My previews are literally one inch of packed animation frames.
I just want the icons bigger, not the entire window, btw. Basically, your vision accessibility is severely lacking if there's no answer to this problem.