The solution I've used for this, which was a bit tedious but not that hard to implement, was sprites for the icons/emojis and SDF for everything else. I'm sure there would be other solutions too, like layering. So it's not useless, you just need to get creative to overcome the limitations. Like everything else in 3D graphics.

Yes, I agree — I did write “useless on its own” to highlight that you need to extend the SDF rendering model with a different one to handle actual user-generated text.

Use.GPU handles this just fine: it uses a subpixel SDF mask with a plain color image. You get crisp edges, just the interior is a bit blurry.