What's the purpose?
I made a research of how level requirement is calculated, what does tell for example that Temerian Armour is specifically level 4. Well I find it (thanks to Partoutatix) and my first reaction was: This is not right!

Here the mod change:

• Level for swords is rounded down, instead of rounded up.
• Any additional damage such Fire Damage increases correctly the level requirement like how Silver/Steel damage increases levels.
• Quality no longer deplete Level Requirement. Now Relic/Witcher quality have +1/+2 Level Requirement, for example Temerian Armour is level 5.
• Level requirement for Bolts and Crossbow are expanded and (hopefully) balanced.
• Removed the randomised generator and quality dependant for Autogen system.
  

The main idea is making how valuable are relic and witcher equipment. If you find them or got as reward, usually means "you're doing great, here a very good sword", but they should be hard to get and not very practical. So, by purpose, I just make that great equipment requires a little bit more level than a regular "Magic/Master" equipment.

Also, as you know, each equipment has different stats (especially if you use Essential Weapon Rework for example), but the vanilla game randomised the amount of armour/damage and stats. This mod simply removes the random generator, so if you find two swords at the same times, now the real difference is the effective stats. No longer thinking "I take that sword because it does much more damage".

No predefined armour/damage, nor XML/Bundle Text, have been changed!

4.04 Next-Gen compatible!

Installation
For newcomer/beginner: I invite you reading The Tome of Witcher 3 Modding

0 DON'T USE VORTEX!!
1. Use Witcher 3 Mod Manager, or extract the files in your game's directory Witcher 3 Wild Hunt GOTY Edition.
2. Launch Script Merger and merge the script if it conflict.
-1. Be careful your equipment in the inventory isn't at the same level as Geralt or they might got higher level requirement.
Thus unable to equip... unless they are equipped that is so don't drop it!


How to uninstall?
Delete the folder "modSimplifiedLevelRequirement"

Compatibility and Conflict
Reminder: Next-Gen compatible!
This is a script mod only that affects the following scripts:
- game\components\inventoryComponent.ws
- game\gameParams.ws

Obviously, any "Level mod" such No Level, Item Levels Normalised or New Game Plus Plus, are incompatible to this mod.
But the listed mod in the Recommended Mod are fine to use.

Recommended Mod
Below are the list of mod I recommend with mine:
- No Random Gear Stats and Stat Values: Most Recommended. All equipment have their predefined stats, not added by random.
- The Essential Weapon Rework: Statistics rework of all Relic and Witcher swords to make them unique and powerful.
- Crossbow Rework: Statistics rework of all crossbow to make them unique and a bit powerful.
- Balanced Item Level Scaling: Dynamically change the armour/damage based on the level in a more balanced way.
- Balanced Damage and Scaling: Fairly balance the damage against enemies and the enemy upscaling system.

My other Mod
The Legend of Zelda: Tears of the Kingdom 
The Witcher 1 Enhanced Editions 
The Witcher 2 Assassin of King 
The Witcher 3 Wild Hunt 

Special Thanks

Tools used: Notepad++ (with compare plugin)

Andrzej Sapkowski (Author) and CD Red Projekt (Game studio) for the creation of The Witcher universe.

Part of the Project Witcher Elements