Unsortable Nonstackables

The following is a list of all nonstackables that cannot be sorted without allays or voiders by sustainable means:
All armors excluding netherite
Pickaxes, shovels, swords, axes, hoes, excluding netherite.
Bow
Mace
Crossbow
Trident (technically sortable but not as an item)
Spyglass
All goat horns
Totem of Undying
Elytra
Fishing Rod
Carrot on a Stick
Warped Fungus on a Stick
All horse armors
Saddle
Wolf armor
Milk Bucket
All banner patterns
Buckets with fish, axolotls, or tadpoles (kills the mob inside and sorts as a water bucket)
The following is a list of nonstackable items that can be sorted but share a category with other nonstackables which they cannot be differentiated without the use of allays.
All potions, including lingering from splash and drinkable
All netherite tools and netherite armor
Boat wood types
Chest boat wood types
Bed colors (bed sorting leaves all beds as one of 2 colors)
Shulker box colors
Disc 11 and Creator (Music Box)
Wait and Creator discs
Pigstep and Precipice discs
Otherside and relic discs