As some of you may already know, tessellation is going to be completely removed from Unreal Engine 5.

Source

For those who do not know what these technologies are, I will try to explain them as simply as possible:

• Tessellation dinamically subdivides a mesh and adds more triangles to it. Tessellation is frequently used with displacement/bump maps. (Eg. Materials that add 3d detail to a low poly mesh).
• Nanite makes it possible to have very complex meshes in your scene by rendering them in a more efficient way. Therefore it requires already complex meshes.

Nanite does not replace tessellation in every case, therefore you can't say that it is made obsolete.
For example:

• Displacement maps - Tessellation can be used for displacement maps, a functionality that nanite does not have.
• Procedural Meshes - Nanite does not work with procedural meshes (Nor will it ever, the developers have stated that it will not work at runtime). On the other hand, tessellation does work with procedural meshes, saving time and resources as it is much faster than simply generating a more complex procedural mesh (+ also displacement maps, again).
• Increasing detail of a low poly mesh - Nanite does not increase the detail at all, it only lets you use meshes that already have high detail. Tessellation can take a low poly mesh and add detail.

This petition is to let Epic Games know that the Unreal Engine community would like tessellation to stay in Unreal Engine 5, as it is a very important feature for rendering and procedural mesh generation. It can just be added back and coexist with nanite.