Download all songs in my library

[planigan]

In the mobile app (iOS), the Download switch is available for all Songs in Your Library. Why isn't the same option available for the Windows 10 app?

I just bought a Surface Pro that I plan to bring on flights quite often. I don't organize all of my music into playlists, so it is going to be a huge hassle to if I need to create a playlist out of all of my songs in order to listen to them offline.

Can anyone shed light on this apparent oversight?