Only a few old technologies really die. The rest find a tiny niche where they can live forever. Niches like compatibility, nostalgia, quality or aesthetics, off the top of my head. That is, you might keep an old computer around because it's the only thing that runs a certain program correctly, or you might like to be reminded of the past time it represents. It may be of higher quality than new things, like built-to-last kitchen appliances, or it might appeal to you on a purely artistic level, made with a style and flair that's a bit different and quirky compared to what's available today.
Mokalus of Borg
PS - You can still buy typewriters online.
PPS - And a lot of other obsolete machines.