Earlier quoted context omitted.
“Scale-independent layout” (layout that ignores pixel aliasing) really requires PPI over ~200, that is, more than most desktop monitors provide. We’re still just not there.
It’s going to be a bloody mess for a long time, because the choices for how to handle resolution independence are all inherently filled with compromise. With font rendering, I think there is hope. Horizontal subpixel positioning with vertical hinting seems like a good tradeoff to me. Grid fitting vertically is not too jarring, and grid fitting horizontally to subpixels instead of pixels looks pretty good too, on low…
The border width should get snapped to the physical (sub-)pixel resolution as part of rendering. Typically, this should come with changes in contrast too, such that if a line is forced to become thinner it also gets drawn with higher contrast wrt. the surroundings, and vice versa. All of this stuff can be made to work.
Also, if you are forced to render a canvas at a resampled resolution because existing APIs give you no other choice, at least do it right using a proper Lanczos-style resampling. This might end up with a quaint "watercolor" effect but guess what, that's a lot better than a blurry, eye-fatiguing mess.