I use a Huawei Smartphone and have my L&P W1 connected to it via the USB-C. For 1 hour listening music it drains 5-6% of my battery. That is not at all any significant - so unless somebody listens for hours with his IEM's there should not be a big problem for battery drainage.
Having said that - i bought a USB-C splitter (there are several different models out there) - one of which i show you as a photo - the one i like quite well. Others are a Belkin USB-C Adapter or a Cable creation adapter - both of which take USB-C from a charger and slide it through to the Smartphone and at the same time transfers Digital Audio back via the other connector (which is the one i connect the L&P W1 to).
Having said that - because the W1 drains so little battery - i hardly ever use this dual USB-C Adapter anymore...
I do agree that it is a big question if a bespoke portable Audio player still has some value. Memory is cheap and now there are 256 GB or even 512 GB Mem Chips out there for a little price. Android phones can download apps (i use poweramp) and off you go ! The sound quality is simply top - i don't know where and how a bespoke device is still needed. AND i do not like to carry too many devices with me anyway.
My 2 cents on this topic and yes i will buy the W2.
