Here, pick from various amounts of these 3 options, these have been the explanations for basically every ass tier AAA game in the past couple of years:

1. UE5 is very flashy, ‘developer friendly’ garbage that explodes in complexity when you try to do any serious modification/customization of the engine or render pipeline

2. None of these AAA devs that are supposed to be experts in UE5 actually are

3. Management is beyond incompetent and tells devs to do things that are actively bad/harmful/destructive/broken.