That can definitely work, however the micro-usb and even Thunderbolt (Apple style) connectors will fail after repeated use. Granted “repeated” means thousands of times, but when folks are keeping phones for 4 or more years, this failure does occur often on a long enough timeline. This is why I purchase wireless charging phones, which most of the newest models now support, and keep a wireless charging battery in my backpack.
Only problem I see with this is you can't both charge and use at the same time, which you can with the cabled battery pack. I assume that a wirelessly charged phone will also allow a cable connection (I've never looked into wireless charging as I have never had a cable problem)?? If so, that potential drawback goes away.