
I once did that with a Samsung powerbank I have. Daisy chained the powerbank to charge itself and a phone in sequence.
The only thing that failed afterwards was one of the cables, but suffering a loss was definitely the reason I didn’t attempt to do that again.
Okay so not exactly zero, but until a heavy hitter like Samsung won’t even consider, worldwide adoption is going to be low - their flagship just stuck with Qi 1, even though the standard existed for about two or three years at this point.