In the video, youtuber used the Wabbajack program, which has assemblies with a huge number of mods for many games. Among the modifications installed in the game, one can distinguish the FNENB mod, which makes the picture more realistic, and Reshade, which improves the color gamut.
The game with 600 mods was played on a fairly powerful PC with a Ryzen 9 3900X processor, a GeForce RTX 3090 video card, 32 GB of RAM and an SSD.