Full [2021]bright-mod-fabric-1.21.4.jar | File Name-

For players, Level 0 darkness is problematic. Even with the "Moody" brightness setting turned up to 100%, pitch-black areas are essentially unrendered. You cannot see enemies, you cannot see ores, and you certainly cannot appreciate the building details.

A common source of confusion is thinking Fullbright functions like the Night Vision potion effect. File name- Fullbright-Mod-Fabric-1.21.4.jar