I have a large music library in iTunes on PC, which contains music I have purchased from Apple and music I added to my library from physical CDs.
I have an iPod Touch and access to Apple Music. When I try to add something to a playlist or my library on the Touch, I am asked to use iCloud Music Library.
I eventually relented and am uploading my music library to iCloud Music Library to get the added features.
My question is -- why do I need to use iCloud Music Library when all my music is physically synced to the iPod Touch anyway? The Touch doesn't need to access the music in iCloud, as it is already synced.
After activating iCloud Music Library on iTunes and the Touch I can now add albums to a playlist via the Touch, which then appear as a playlist in iTunes, which is pretty nice :)