I worked as a recording engineer for several years. The first studio I worked at, the B room had an SSL 6000 G Series and a Pro Tools 888 system hooked up to an

I worked as a recording engineer for several years. The first studio I worked at, the B room had an SSL 6000 G Series and a Pro Tools 888 system hooked up to an Apple machine running OS9. This was 2008, so already old back then, but with the way it was configured plus the 888 system, it was still valuable. I have friends who work in water treatment infrastructure, and out of necessity carry laptops with VMs for DOS, windows 3.1, etc. Even my AD/DA converter at home is no longer supported. I use a 2010 mac mini running OSX 10.11 with it. As long as people are using older hardware that interfaces with a computer, older OSes and machines will be useful.