VR Tips UI Font Blurred

Hi, folks. I need to make a guide UI to help people know the button function, just like the Reference effect picture.
Just look at the second picture which the font size is 24. However, it’s too big for displaying more UI. So I set the Font size to 3, then it blurs. Finally, I choose to ignore the font size, just scale the widget component to solve this issue. But I still want to know why this happens and how to fix it. And if you have another method to get a similar effect like the Reference effect picture, feel free to share it here. Thank you very much for your answer.