Even if other codecs can beat it on size and quality, if the ergonomics of the playback library are substantially better for game developers (as they claim) then that would make it a compelling choice.

If it ain't broke don't fix it. Games aren't under the bandwidth pressure streaming services are so there's not as much reason to switch to something like AV1.

Bink can handle 4K HDR decoding even without hardware accelerator chips by using regular GPU shaders. That means you don't need to fiddle with any system library and it just works. It's also great for streaming overlays, animated textures, explosion effects because it can render in HDR inside your core engine loop. So if you use deferred shading, you can even stream material properties, e.g. an object becoming more metallic during a texture animation video.