Tidal, Deezer

Could someone with experience with music subscription services please advise. My confusion is that these music services advertise that you can download music for offline listening. Wouldn't that be putting music files in your storage...creating a music library? I have had itunes and rhapsody, both of which you can download music files into your computer. Surely there must be others you can do the same? Thanks for any advice
Anyone here to build an app for personal or business usage suggest you check here; https://multi-programming.com/mobile-development

Our apps are invariably designed to run efficiently on iOS and Android. Whichever platform you use, we can develop the perfect app for you!

to answer some of the questions:
Metadata-who cares.  I'm listening, not looking
Why download/offline-I travel a heck of a lot.  Can't get data at 30k feet or when driving in the back country.  Also, my turntable doesn't work in my car.
Quality-it's quite good.  Remember the limitations in car audio or $200 headphones.  At work I have a nice system and actually stream tidal through my Chord Hugo and it sounds very nice.  Yes, I can get better resolution at home with my main system but my turntable works fine there.
Finally, I like playlists, either streaming or offline.  Sometimes I'm lazy or preoccupied.  
Don't like iTunes audio files, Tidal and Deezer music are music streams, which are cache files. You can download them as local files via the official way. 
If you'd like to locate Tidal music on your computer, you need to look for an excellent tool for Tidal to figure this out. AudFree Tidal Music Converter is such a wonderful Tidal converting tool that can not only download Tidal music to your computer but also convert Tidal to MP3, FALC, WAV, AAC, etc. So that you can enjoy Tidal music world without a problem.