Adamantite Pickaxe

It opens nothing new. Every block it breaks, the previous tier already broke, so the ore buys you nothing except speed. That same ore goes into an armor set where the benefit shows up in every fight instead of in how quickly a tunnel gets dug. The next thing that genuinely stops you is Chlorophyte, and neither this nor the drill version will scratch it, so the real upgrade comes off a Hardmode boss rather than out of the ore chain.

Out of the box the drill is faster, which is why most players grab it and never think again. The trade is that the drill ignores mining speed bonuses completely. Stack a mining potion with mining gear and the pickaxe pulls ahead, and it reaches further, which matters when you are stripping a wall sideways rather than sinking a shaft. No buffs, no bonuses, take the drill.