Maybe the Windows installer could bundle a better theme by default. I tried to address the very same problem @alexnerd123 is facing on macOS and tweaked the Prof-Gnome theme here for this purpose:
https://github.com/geany/geany-osx/tree/master/Prof-Gnome/gtk-3.0
I think the result looks quite good both for the light and dark variant. Maybe Windows binaries could use this theme too.
<img width="1260" alt="Screen Shot 2021-12-23 at 14 51 36" src="https://user-images.githubusercontent.com/713965/147249913-85fa9a96-af07-4a29-a52a-f8c6ebbfe4a1.png">
<img width="1260" alt="Screen Shot 2021-12-23 at 15 02 33" src="https://user-images.githubusercontent.com/713965/147250946-dfd4a133-2c07-4c67-9375-b243cc40dc7d.png">