Been using the Dragonized version of Garuda as my DD for a few months now.
So, I'm running the KDE version. I just ran into another OS called CachyOS, and they have this really beautiful theme called Emerald (github will be posted).
The theme is not in any of the stores, but is on GitHub.
/usr/share/plasma/ is the path for system themes, user themes should be stored in ~/.local/share/plasma/. It probably won't matter, but do keep in mind sometimes system directories can be modified or overwritten with updates while directories in home will be left alone.
We mark here the solution, not the implementation.
Even if you have changed it.
A reboot and the selection in the system settings (GUI) you probably have not found.