Hello,
Currently in game chickens are the only animal that drops feathers and the feathers are only really used for arrows and a quil so in practice mostly arrows, and I had some thoughts about it.
Firstly, chickens can drop between 8 and 16 feathers while irl chickens only have 10 primary flight feathers, which are the feathers you'd need for arrows. You could find one with less than 10 if they end up losing one or one gets damaged or something but you wouldn't find 16 usable feathers on any bird irl.
Second, irl chicken feathers aren't actually used for arrows really because they are too small. Typically feathers for arrows are goose or turkey feathers.
Which brings me to my 2nd suggestion which is the inclusion of other fowl, I am probably not the first person to suggest this but I think it's a little strange chickens have a unique meat drop that no other animal has while ''redmeat'' is dropped by most other things. Other fowl would add other sources of poultry and eggs to the game and animals like cassowary could even form a threat to the player much like sheep are. Waterfowl like ducks would also be very interesting to see on the water as opposed to just fish. Different kinds of fowl could be balanced so that they produce less eggs than chickens but produce more usefull feathers or more meat so the player is incentivized to try both.
Different types of feathers might also be used to craft different quality arrows. Perhaps chicken feathers might still be used for arrows but larger feathers create stronger arrows or arrows with a smaller break chance?
Other uses for feathers might be:
1) Bedding (technically irl you wouldn't use flight feathers for these so you'd have to strike a balance between realism and gameplay of course)
2) Decoration obviously
3) Fertilizer
