Minecraft's item content is more centralized on building and crafting, whilst Terraria's item content is focused more upon exploration and battling. If you were to compare the two games, the only thing you could really say is that Minecraft is better for sandbox building, and Terraria is better for adventure.
Terraria has a much better progression system, more content, and advancing through the game is more enjoyable. When it comes to building, I enjoy them equally, but they give you a different experience. Minecraft is what you make of it. There is always something to do if you're willing to look for it.