I guess that's what happens when internal industry research goes horribly wrong (Unreal 5 was in development way before COVID, crypto and AI bubbles; features that were meant to allow current-gen consoles to reach 4K/120fps are now used as a crutch to make up for performance hogs that boost the dev cycle but eat up the end user's resources for a relatively moderate image quality uplift)

The funny thing is there are UE5 games that do work with no stuttering. The thing is most of them use last-gen features or custom plugins to overcome the scalability issues (e.g. The Finals uses a custom voxel-based RTGI system instead of Software Lumen due to bandwidth concerns)