SolidWorks 2021 seems to have reversed the effect of the "Enhanced graphics performance" toggle in their settings with the release of 2021, at least on our CAD PCs (Uses NVidia P2000 graphics card).
After much research, I stumbled upon the answer on my own, knowing how SolidWorks is often seems to break something else when they repair something, or make things not-so-intuitive. Still a powerful program, but it keeps us CAD-Admins and Power Users on out toes for sure.
So, if you feel your text blurry relative to previous releases (we went from 2019 SP5 to 2021 SP1), You will need to go to:
"Tools > Options > System Options > Performance > Uncheck - Enhanced graphics performance (requires SOLIDWORKS restart)"
This option was checked for me when the text was blurry, and after unchecking it and restarting SolidWorks, my text was much clearer on higher higher resolution monitors.
Here's an example of the two scenarios.
With the "Enhanced graphics performance" option Checked:
With the "Enhanced graphics performance" option Unchecked:
As you can see (hopefully), the text is much sharper and crisp with the option unchecked.