The Mushroom Biome is the only biome where hostile mobs do not spawn at night. This makes it the safest place in Minecraft and the best place to build a home. There are also no mobs in the cave systems, allowing for safer mining.
However, be aware that mob spawners will still work. So, if you do see any zombies or spiders, then you know there’s a spawner nearby. Overall, the Mushroom Biome is a good place for a base.