Here we go. You wonder why a scan looks like (whatever) I made three scans of the same chip, same scanner, everything the same, never moved the chip, except I resized two, to make them all the same.

You can see on the right, what happens when you make a smaller scan and enlarge it. On the left, when you make a large scan and reduce it. In the middle is the original scan at 100%, no resizing.

Judge for yourself. It's not the scanner, it's what you do with it. In this case I'm using a HP Scanjet 5P from 1996 vintage. It's not nearly as good as anything you can buy now.

Find the size for the original, that is the size you want to use, and it will look it's best.