Well, my fault again. I remember a daemon doing XFT rendering for plain X, from Debian Woody days.

You were half right which is something for stuff this old. I'd entirely forgotten about the font servers, and looking at them, at least xfsft does use FreeType/Xft. It's just that it's still rendering to monochrome bitmaps.

It'd have been a logical extension to figure out the changes to support AA for them as well, so it's a reasonable assumption, especially given the short cutover before Xrender took over and we started getting AA most places. Indeed, Xrender provides all the server-side infra that'd have made it easy-ish to do, by allowing glyph sets with depth...

In retrospect it's also surprising that it wasn't done, because it wouldn't instantly given AA to a lot of applications "stuck" on server side font rendering...