This document describes PNG (Portable Network Graphics), an extensible file format for the lossless, portable,
well-compressed storage of static and animated raster images. PNG provides a patent-free replacement for GIF and can also
replace many common uses of TIFF. Indexed-color, greyscale, and truecolor images are supported, plus an optional alpha
channel. Sample depths range from 1 to 16 bits.
I’ll agree for those use cases, but not everyone is making icons, stickers and emoji.
They are using them, however. They’re visiting websites with them, using apps with them, and so forth.
OK, and the kernel is written in C and assembly. Should they know both of those as well?
No, but it should still work. Getting rid of alpha channels would break all of that.