I see font rendering is not adapted to 3D in the screenshot, so it is not yet ready for serious UI work. I presume curves are not rendered in an adapted way either, so everything will look pixelated around the edges.
The current implementation of SDF conversion is just a tad too slow to make on-demand glyph rendering comfortable right now, so there's a bit of additional optimization work that needs done before we can switch to that. We were just prioritizing language support over text clarity to start with.
I'd say it's primarily a question of polish and feel! Those that can't spot it right away would still prefer SDF fonts in a side-by-side, and the difference becomes much more clear if you start getting your head really close to the text. I consider it to be an essential feature for a 1.0 version, but not a blocker for right now.
The current raster technique should actually be fine for smaller text, there's some super-sampling going on in the shader that should help a bit here too! I'm not entirely certain what else could be improved on in this case besides font selection, I'd be open to suggestions or tips :)
Something like https://github.com/servo/pathfinder (newer) and as you mentioned SDF (older) are the latest approaches.
SDF is probably still the most realistic path for now, but I guess that may depend a bit on what comes up :)