improving the functionality of old mobs

There are mobs that have been forgotten and barely touched, I'm talking about the former bears, llamas and mountain goats, horses and donkeys. All of these mobs except the horse are completely useless and almost no one notices or uses them. Why not add food functionality to them, or are the developers' position unwavering and nothing like that will be added? And since we're talking about forgotten mobs, why was the polar bear so neglected? Cows, pigs, and chickens have different counterparts in different biomes, but bears don't.