Beds are overpowered, but also vital for many players.
The difficulty spike that is nighttime arguably plays a major part in keeping Minecraft interesting, especially the first few days, and being able to skip it feels upfair.
On the other hand, that "difficult" moment usually ends up being sitting on a pillar doing nothing for 10 minutes. That's not difficult, just annoying.
This datapack/mod fixes this by making phantoms spawn when you sleep, so if your bed isn't protected, you will get attacked. By enouraging players to make a proper shelter, you can sleep when at home and safe (so night wouldn't pose a threat anyway) but not sleep when you're out in the open (where mobs can get you). Now, if night is likely to be a fun challenge, you're better off not sleeping, but if it will probably be boring, you should sleep instead.
Also useful for modpack authors or players who want to balance beds more so that you can't just plop a bed down in the middle of nowhere and skip the night.
TIP: If you want to turn off phantom spawning for when you DON'T sleep in a bed for 3 nights, turn off the doInsomnia gamerule either when creating a new world or with the command (requires cheats) /gamerule doInsomnia false.
FAQ:
How do I use it?
When creating a new world, you can add datapacks through the menu.
Can I install it as a mod?
Sure, check the Versions page for downloads. This will make it install for every world instead of just whatever you put it in.
Safe to uninstall?
Yup!
As a datapack, take the .zip out of your datapack folder.
As a mod, remove the .jar from the mods folder.
Can I use this in Modpacks?
Sure! Just please leave credit :)