About a year ago the opposite was true - Facebook was almost fully functional over lynx (or links2 in my case), while Twitter was... less so. (And obviously G+ wasn't.)

Interesting. A few years back it wouldn't work in Lynx at all- but they returned an error explaining that and included the message "Keep it real."

I must've caught a window where it worked. I recall it was always the mobile version of Facebook, and it couldn't detect the browser. May be one of the differences between lynx and links2.