The charging thing in particular seems like a disaster— the situation is bad enough with dedicated power supplies, where we have Amazon pages listing specific devices and laptop models that are known to work; but then there's this whole classes of setups where the correct behaviour isn't even knowable without directly querying the user. If I plug that USB-C battery bank into my laptop, should it be charging the bank from the laptop, or charging the laptop from the bank? Does it depend on whether the laptop is plugged in or not? If the laptop is plugged in to a current-limited source, should it prioritize charging the bank or its internal battery? Gaah.

Here's what the Android prompt for this looks like: https://www.quora.com/Devices-can-charge-or-be-charged-via-U...