If you are having trouble with themes on arch linux, install strawberry-qt5 from the AUR, and install qt5-styleplugins along with qt5ct to set the theme you like, including gtk2 themes. Strawberry now comes with qt6 by default, which is a bit finnicky at the moment, so installing the qt5 version made it a whole lot easier. This took me a while to figure out, and since this is the first result that shows up on google, I might as well post it for everyone to see.

This is the Dracula-alt-style theme on GTK2.