Steps to reproduce:

1. Open attached project in Unity 2022 LTS

2. Open scene Colliders_MoverInHierarchyComplex.unity

3. Enter playmode and capture CPU performance using profiler

4. Make a copy of the project and open it in Unity 6, then repeat the steps above

5. Compare results

6. Repeat exercise but this time building both versions for a less powerful platform

Although this is a regression on all platforms, the numbers add up very quickly on lower powered device such handheld consoles and low/mid spec mobile devices.

Actual results: 

Syncing Physics colliders is about 3-7 times slower in Unity 6 compared to an identical scene in Unity 2022 LTS.

The variance in regression comes from scene configuration and complexity, but certain complex hierarchy configurations that were already a bit slow in 2022 LTS are now significantly slower in Unity 6.

Expected results: 

Cost of syncing transforms in Unity 6 is on par with or lower than cost of syncing transforms in Unity 2022 LTS.

Reproducible with versions: 

6000.0.26f1

Not reproducible with versions: 

2022.3.20f1

Tested on (OS): 

Windows

macOS

Android

Notes:

For a point of reference, testing the included repro on a low-powered Android device it spends about 3 ms / frame syncing transforms in Unity 2022 LTS and 15 ms / frame in Unity 6 - so 5x as long in U6.