[wvbdmp]

Indeed, the Aeron chair, which became a design classic and the apparently the best-selling office chair ever in the US, only came out in 1994. So about the same time as the web. Not sure if it’s the only office chair design with a dedicated wikipedia page? https://en.wikipedia.org/wiki/Aeron_chair

[voidUpdate]

Depends, is the deck of a battleship an "office"? https://en.wikipedia.org/wiki/Emeco_1006

Theres also https://en.wikipedia.org/wiki/Mirra_chair. (wikipedia has a page for "list of chairs", but not all of them have a dedicated article)

[fusslo]

probably my least-regretted purchase (excepting my dog) is my used Aeron that I bought in ~2014 for $300. Still use it daily