I totally agree. It doesn't make any sense to buy a 23" monitor with that resolution and not use it's native resolution for perfect picture quality. Anything less seems silly unless rubbish picture quality at non-native resolutions is considered acceptable versus the smallness of the pixels at it's native resolution.bear in mind, any resolution other than the native res of 2048x1152 will look blurry and, frankly, rubbish.
The topic title is perfect resolution for 23" but I suspect it should be what is the perfect resolution for a 2048x1152 panel to make text etc bigger but not too big and the answer is there aren't any non-native resolutions to use except when (as said above) rubbish picture quality is acceptable unless of course 1024x576 can be considered an option.
I suspect the OP is looking for perfection out of a situation which cannot provide it, so seriously, consider getting rid of the monitor and buy something which better suits your needs.
