The bug

Crying Obsidian has the same hardness and blast resistance as regular Obsidian, but unlike regular Obsidian, it can be harvested with any pickaxe (including Wood). To me, this seems like an oversight.

I'd either make Crying Obsidian easier to mine or I'd make it require a Diamond/Netherite Pickaxe.

How to reproduce

1. Give yourself an iron pickaxe and place some Crying Obsidian in the world
2. Give yourself the haste effect to test more quickly

   /effect give @s haste 1000000 50 true

3. Start mining the Crying Obsidian
   Notice the block drops, even though you are using an iron pickaxe