Clean F3 is a lightweight, open-source mod that improves the appearance of the debug screen by removing some useless information from it.

Before:

After:

All settings can be changed in the config screen thanks to MidnightLib.

Settings as of version 0.4.4:

This mod not only allows you to remove debug elements from Vanilla, but also from some popular mods:

Distant Horizons
EntityCulling
Iris
Litematica
ModernFix
Presence Footsteps
Sodium
ViaFabric

FAQ

Q: Why hide F3 elements from other mods too? Did the mod authors not include them on purpose?
A: While some mods add elements that are useful for debugging, to most users these don't matter and they just distract from what is more relevant to most players. If you want to report an issue for one of the affected mods however, make sure to turn on their debug info again if they ask you for an image!

Q: Can you add a toggle for ImmediatelyFast?
A: ImmediatelyFast already has a config option built-in to disable its debug info.

Q: Can you add a toggle for another mod xyz?
A: Open an issue on github with the mods name so I can look into it.

Q: Neoforge/Forge version?
A: Clean F3 is currently only developed against Fabric. If you wish to use it on NeoForge however, you can do so with Sinytra Connector. This unfortunately doesn't work with Forge 1.20.1.