I mean that Freehand, for e.g., existed. What it did was thus not fiction. It was doing it so well in the 90's on Windows 98 on computers that sucked.
In other words, we are not limited by what O/Ss can do. Nor by what C++ (etc.) can do. Nor by what the various GUIs can do. We are limited by 1) legal and patent threats and 2) A small work force of unpaid volunteers, but mostly by 3) Overly conservative slavish devotion to SVG standards.
On point 3 I feel SVG has gotten to a great place, but it took so long. Along with this note of alarm sounded by respected members of the SVG and Inkscape community, perhaps it's time to reboot goals?