SceneKit is actually just straight up deprecated now: https://developer.apple.com/documentation/scenekit/

I imagine it will still be around for a long time because Apple and a lot of large third party apps use it for simple 3D experiences. (E.g. the badges in the Apple Fitness app).

Apple wants devs to move to RealityKit, which does support non-AR 3D, but it is still pretty far from feature parity with SceneKit. Also RealityKit still has too many APIs that are either visionOS only or are available on every platform but visionOS.

Microrant: I absolutely loathe when I am told "move to new thing. Old thing is deprecated/unsupported" and the new thing is incredibly far from feature parity and usually never reaches parity, let alone exceeds it. This is not just an Apple problem.