Well I decided to research it. I know from my own programming experience as far back as atari 800xl and commodore 64 and dos 3 I have seen frame buffers. When was it standardized. That is the real question.
First there isn't a current graphics chip manufacture that produce a chip what so ever without framebuffer. - zip zero zilch
Intel, AMD, Nvidia, S3/via tech, SiS, all support earlier versions of opengl most support up to 1.3
AMD, Nvidia and intel keep up with more current releases.
Opengl 1.1 came out in 1997.
But frame buffering even supersedes opengl you can find it back in the VESA standards most VGA cards supported frame buffering.
However it was standardized in the Vesa Bios extension that was 1994. Which is still in use.
Found wiki has a fairly good article on framebuffers surprisingly it missed the standardization in VESA.
https://en.wikipedia.org/wiki/Framebuffer
The same seems to hold true for mobile devices and embedded especially if capable of opengl.