I’m an Unreal Engine game dev and there’s some partial truth to this.

It’s true that if you use all the new fancy bells and whistles like Nanite and Lumen that you will very likely raise your minimum specs by quite a bit.

There’s more to this then just Nanite and Lumen, but these are the biggest offenders, so I’ll focus on them.

Nanite can be thought of in basic terms as a dynamic LOD system. LOD stands for Level of Detail and is used to reduce the amount of polygons (triangles) the GPU needs to render when an object is far away, swapping the 3D mesh/model with a more simplified version. A single mesh can have multiple LODs for various distances. For the game dev, this saves a huge amount of development time not thinking about LODs and the need to create them. For the player, this prevents pop-ins when the game engine is switching between LODs. What Nanite offers is incredibly complex geometry for meshes, highly detailed rocks and trees for example. One thing that Nanite suffers from is called Nanite overdraw. That is when many Nanite meshes overlap each other from the perspective of the player, like trees in a forrest. In this case the frame time goes up (FPS goes down) due to too much processing relative to traditional methods.

Lumen is the dynamic global illumination system in UE5. It offers (most of the time) superior lighting quality and also bounce lighting (when a window or a door is open in a dark room and light comes in and bounces around, lighting up the room). When a game uses only Lumen, there’s no static lighting which is baked before shipping the game. Baked lighting is incredibly performant, but the shadows from various stuff in the environment is static/baked, which means it can’t move. For game devs, this allows very quick iterations and much quicker dev time overall for the various scenes and environments. For players, this offers much better lighting and visual fidelity. However, like with Nanite, this increases the minimum specs.

There’s nothing really stopping devs from just using the traditional tools instead of these new dynamic tools. That would of course take longer, increasing dev time, and certain aspects would need to be more faked like before (day/night cycle with baked lighting for example).

Most UE5 games that have been released are using somewhat early versions of UE5. Epic releases 2 versions a year and we’re currently at 5.5.1 STALKER 2 is using some version of 5.1 IIRC. That means it’s using a very early version of Nanite and Lumen.

Ultimately it comes down to what the dev studio wants to use and these decisions have consequences, both good and bad.

There’s a YouTube channel called ThreatInteractive that goes deep on this. The guy comes off as a bit too hostile for some and maybe hyperbolic, but the core of what he’s saying is true.