But over the past few years/decades, as glyphs have exploded in number, I've been finding myself wanting a totally different system of font definition.
I want fonts to be made out of just a handful (at a minimum) of primitives -- e.g. here's a vertical stroke, a horizontal stroke, diagonal strokes, what various serif endings look like, here are what the bowls of letters look like, etc.
An entire Latin alphabet can easily be extrapolated from that -- but also Cyrillic, for example. And then you can go further, and specify elements used only in Greek, and so on...
But the idea being that there's a "default", boring, generic universal font template that covers all glyphs. And that a type designer simply modifies parameters as desired.
Now the designer can go as far as they want, with individual glyph adjustments overriding the automatically-generated ones, custom kerning pairs and whatnot.
But the benefit would be that, even if they don't, then for a Latin alphabet you already get Cyrillic, Greek, Arabic, Chinese, Japanese, etc. characters that match well (in x-height, stroke width, etc. as needed).
The more I work with typography, the more I think static font outlines for each glyph are the wrong way to represent things. Smart parametized outlines are what we need.