It used to be difficult to scan qr codes with black backgrounds and older phone apps will blast their screen LED lights to make it easier for the qr scanner to read it, but in the end, all you're doing is scanning a qr code usually.

I had the black background issue at concerts for years but I haven't had that problem in the last 2 years.

HDR maybe? A literal PNG can now tell the screen to go full brightness on selective parts or the whole thing.