I'm not a part of this space personally so I can't say for certain, but one answer could be the not-PCs and cloud. Some people find a tablet with a keyboard perfectly adequate for their all-office needs. Even if the "sys-admins" still need PCs that is still a very substantial conversion of the market share away from PCs. If you reflexively scream at the notion of how horrible that would be for your working process, I do not blame you but note it could work for some.
Do you really need to be part of “this space” to know that Microsoft has a 90% share in PCs and most of corporate America and even personal computers are running Windows?
Even the people who like tablets are still buying Surface laptops - running Windows.
They aren’t buying iPads and definitely not Android tablets.
Even a lot of iPad aficionados are moving back to Macs now that they have a lot of the advantages of iPads - slim, lightweight and ridiculously long battery life.
