SUMMARY
I've been trying to find out the reason why GPU usage are low in Wayland compared to X11, not matter what settings and environment variables you set. Among other issues related to VRR/Gsync.

https://discuss.kde.org/t/low-gpu-usage-in-wayland/28297

I recently found a few things that could related to all this in some way and could be a bug. 

Confirmation was done through the command reported by another person, and I got the same results here with all settings from the UI and through environments disabling vsync/vrr/triple buffer and everything else that is possible.

https://www.reddit.com/r/linux_gaming/comments/18lxzwm/comment/ke3mpwy/

STEPS TO REPRODUCE
1. Install: https://aur.archlinux.org/packages/drm_info
2. Type: drm_info | grep VRR_ENABLED

OBSERVED RESULT
│   │       ├───"VRR_ENABLED": range [0, 1] = 0
│   │       ├───"VRR_ENABLED": range [0, 1] = 0
│   │       ├───"VRR_ENABLED": range [0, 1] = 0
│           ├───"VRR_ENABLED": range [0, 1] = 0

EXPECTED RESULT
To not be enabled, all everything else are disabled.

SOFTWARE/OS VERSIONS
Operating System: CachyOS Linux (Arch)
KDE Plasma Version: 6.2.5
KDE Frameworks Version: 6.10.0
Qt Version: 6.8.1
Kernel Version: 6.12.9-3-cachyos (64-bit)

ADDITIONAL INFORMATION

Inside the the first url, it should contain other relevant urls for similar topics. Like the similar low GPU usage when having AsyncFlipSecondaries enabled in X11, where if all are disabled in X11, the usage are close to full or full.