blurry monitor

Hi. If you set a 2560 x 1440 (2k) monitor to 1920 x 1080 resolution, will that be the same as an actual 1920 x 1080 monitor? Can you tell the difference between a a 2560 x 1440 monitor set to 1920 x 1080 and an actual 1920 x 1080 monitor? Or will there be a difference like blurry or causing...

Text and images on my new ASUS TUF VG32VQ monitor seem surprisingly blurry and boxy given the 1440p resolution, and I'm trying to get to the bottom of why. Below are a few comparisons to another (admittedly more expensive) 1440p monitor that was on display at the store. Here's the store...