Shroomite Digging Claw

It swings fast enough to erase a tunnel, but you have to be almost touching what you want gone. For carving an arena or sinking a shaft that is fine. For grabbing a vein you spotted across a gap, or clearing a ceiling above lava you would rather not stand next to, keep a longer reaching pickaxe on the bar and swap. Most people carry both and stop thinking about it.

Push mining speed high enough and you remove blocks quicker than you fall through the hole you are making. Straight down, that means free fall the whole way with nothing under you to break it. Get wings, a bottle jump or feather fall sorted before you try a long vertical shaft, or you will find the bottom the hard way.

The attack rate is absurd and the damage is not far off a real melee weapon, so anything willing to stand next to you dies quickly. Knockback is almost nothing, which means nothing gets shoved off you, and the same short reach that annoys you while digging keeps you inside the hitbox where the hits land. Fine for clearing cave trash. Wrong for a boss.

Light and Legendary pull in opposite directions. If this is your digging tool, keep Light, because mining speed is where the real gain sits and the combat use is a side effect. Only chase Legendary if you genuinely plan to fight with it.