Yeah I understand, I was just increasing the accuracy of information by a marginal amount.
I’d have to say that I still think Star Metal should be the best tools. Star Metal is far more rare and more difficult to obtain than Obsidian. Obsidian is a relatively soft material, as mentioned above, and is insanely common. You can harvest many thousands of obsidian in mere minutes. You can’t do that with Star Metal without something like x20+ harvesting.
You can also craft most obsidian tools at the blacksmith bench in your base. All of them except the skinning knife, I believe. So you do not need a special forge; you do for the weapons, but this thread is about tools.
The only reason for Obsidian to be the best would be “because fantasy”. There’s no logic behind it. (The only Acheronian tool is the Pick and I’m not even sure if it can be obtained legitimately, so Obsidian is basically the best.)