I just find it so much easier to plug my controller in after every use and let it charge for the at least 16 hours a day I’m not going to be using the thing. Plugging batteries into a battery charger is not nearly as simple as plugging the usb cable in, I’m not saying either is difficult but I have plenty of AA and AAA rechargeable batteries around the house but I can’t find my charger lol. The fact almost non of the battery packs on the market make use of the built in battery pack charger baffles me, they almost all need to be plugged into the battery and won’t charge if plugged into the controller.
I have 4 or more usb cables plugged into my pc that I can just plug into the controller to charge. I don’t foresee that ever being less preferable than using rechargeable AAs...
I did get a pair of Duracell AAs in the box with my new controller.
Sounds fine if the battery packs you like are available. I had a look and there's a wide variety of options including packs that let you stick the whole controller onto a dedicated charger so you don't need to connect any wires.