It seems people don't understand that streaming and downloading is not the same thing, and you CAN'T use the terms interchangeably, no matter if technically speaking, the same bits are flowing through the wire to you.
- You play a file that is stored elsewhere.
- The file does not need to be moved or copied to the device that is playing it.
- The source of the streaming must be available and turned on.
When streaming, you are not reproducing anything. Nothing is copied or saved.
Licenses for streaming only allow remote playback of material stored in one location, not reproduction.
- You make a copy of a file stored elsewhere.
- You are storing this file on your own device.
- The source of the download does not have to be available after download; you are making an independent reproduction that in turn, can be reproduced again.
When downloading, you ARE reproducing the material.
Licenses for downloading allow reproduction of the material.
As you can imagine, copyright law applies differently to streaming and downloading because one is a performance, the other is a reproduction.
Licensing for performance (youtube) and reproduction (youtube downloader apps) are distinctly different. Youtube licensing (as given by uploaders/producers) allows their public performance of videos stored on their servers, not reproduction to any viewer/listener. The same way at a concert you are allowed to listen to the performance but not allowed to record it.
If after this you still don't understand the difference, then I give up trying to teach.