Off-topic: why does the Firefox icon has that unappealing black background?

I don't understand why lately on iOS, MacOS, Android etc the app icon has that black (dark blue?) background. The Firefox website does not use a dark background icon anywhere, there's not one available in the design kit, although it does mention the preference for either light or dark backgrounds due to the color gradients being potentially confusing with mid-tones and color mixes. I still don't see the need to distribute such a broken-looking one - it makes it look like they messed up the transparency setting on a png somewhere. Compare it to Chrome's (in the OP) which looks fresh, lively and friendly.