Plenty of companies still run hardware. A lot of midsize enterprise and a lot of non-tech/non-software F500. And quite a few won’t move to the cloud - between retailers who don’t want to fund big bad Amazon, hyperactive security departments who (rationally or irrationally) see physical ownership as a necessity, and organizations who have needs which are poorly suited to cloud offerings, it’s not like the datacenter hardware market is completely dead by a long shot.

You can proxy this demand by looking at VMWare sales. Anyone running a large amount of baremetal VMWare virtualization has a large on premise deployment and could find managed rack products like Oxide interesting.