Anti-aliasing doesn't work in QGraphicsTextItem with small font size

QGraphicsTextItem doesn't have any anti-aliasing when the size of the font falls below ~65. As a result, text with continuously resized font resizes in a very unsmooth, jerky way. You can see the lines getting wider and narrower, and different parts of the letters moving not in sync. The issue is especially visible with the font sizes between 20 and 30.

Ideally, I am expecting to see the text resizing like on the modern smartphone screens when the user resizes the browser there, for example.

Please compile the attached example and observe this. I can also upload the video in case you can't reproduce it.

I think the font rendering is eventually done by libfreetype, but I believe libfreetype is able to anti-alias fonts at any size.