Elstar

Yup. Also unless you’re super paranoid, the world is awash in random USB-A ports for charging. So if your plane seat mate has already claimed the AC outlet (if it exists) then all that might be left is a USB-A outlet. So you’d be wise to have that cable and then you might as well have a USB-A charger so the cable isn’t dead weight the rest of your trip.

There is a long-tail of cheap/specialized/old devices that are USB-A powered and are somehow "weird". Some are weird because they have a custom/non-USB connector on the other end (like a baby monitor – so don’t lose that cable!) and some are weird because they don’t have a cable at all (like a voice recorder with a retractable USB-A connector).

Anker makes nice value products but the trade offs they make are always surprises lurking in the background (if documented at all). For example their newer devices sometimes (but not always) have compatibility problems with low-power USB-A Apple devices. Which is kind of bizarre on various levels given how popular those devices are