Minecraft wiki entry for Crying_Obsidian, associated text: When it was originally going to be added in Beta 1.3, it was going to act as a way to reset the player’s spawn point and would be crafted using lapis lazuli. When beds were added, they took this role instead. In 1.16 the respawn anchor was added which is crafted with crying obsidian.
More than 9 years passed between its initial planned addition and finally being available in-game.
The community had heavily requested crying obsidian return in 1.16 as a way to respawn in the Nether, as a callback to its initial intended functionality before beds were added, as an unspecified and likely implied to be undecided way of respawning was mentioned during the reveal.
According to Brandon Pearce, crying obsidian was added when they wanted to have cracked obsidian for the ruined nether portals. They decided to add it as crying obsidian instead because it was more unique and due to high player demand.
The team considered having crying obsidian be obtained by throwing obsidian through a nether portal, or by having regular obsidian be struck by lightning. However, they chose bartering with piglins as a way to make bartering useful.[6]