Unique uses for some tool tiers

Leather can be colored, makes you resist powder snow and the boots let you move freely in it

Gold has the highest enchantability + speed in tools + the armor stops piglins from attacking you.

Chainmail is the only uncraftable armor and is the only one that let's you see your skin below it.

Iron is the perfect balance of price and utility and the perfect middle point for a mid-game gear.

Diamond is the highest tier you can craft and the armor has armor toughness.

Netherite is the only set that doesn't burn and the armor has knockback resistance + is the bestgear of the game.

But wood, stone and copper don't have much, so here are some ideas for them:

Wooden tools should not be able to break some entities like armor stands, boats, item frames and some others. Would be perfect to use for training without breaking armor stands and maybe could have some other utility related to this.

Stone could maybe be the only set that cannot be repaired by combining 2 of the same item in the crafting menu, giving even more utility to copper tools, but should also have something else.

Copper could be the only set that can oxidize, having better stats (damage and mining speed) at first but getting worse the more you use it. Could start at iron level (same damage and mining speed) but eventually get even worse than stone, which could make copper more useful but would require you to repair it with another damaged tool. Also oxidized copper could be used to troll people into thinking that you have diamond.