SCNText rendering without curves, not font-like

SCNText subdivides the 2D Bézier path for your text just like Core Graphics would do if you were drawing it. You can always use the flatness property to make it smoother, but you won't get "sub-pixel smoothness".

To solve this issue you can use a bigger font size, so that the underlying Bézier path is bigger and more vertices are generated when discretization occurs.