Are these PC mods legit or fake?

Saw this on YouTube and was very curious to know how these PC mods work.

Here’s one for AC : Unity

The moder claims to have ray tracing in the game. Graphics also look pretty impressive.

But is it legit? I ask this because it’s very good visuals. I wonder if a modder can produce these results, then why not ubisoft themselves are making a remake kind of thing for this. The visuals alone will sell this game like a hot cake.

I have also seen this kind of stuff for GTA V. Are all those legit?

they’re largely legit, but are simply post-process effects thrown on top, generally using tools like Reshade. They don’t enable any sort of raytracing unless the modder got really great skills to go in and update the graphics engine itself to accomodate for whole new lighting and denoising algorithms. Minecraft has those but the game itself promotes that kind of experimentation at every level including its systems, but all these other games are just compositing and post processing effects thrown on top, or some reflection maps altered to give it a different look. That’s what generally most of these “NEXT GEN FULL RAYTRACING 8K 60FPS” videos generally do, is just crank up the reflectivity on everything until the whole game looks like a hall of mirrors lol.

Then why not game studios implement this stuff?

What am i missing here?

Also, here a gta v mod. Looks fabulous