Dear Debian developers,
I'm just a longtime Debian/Ubuntu user.
I just want to draw your attention on the Noobslab PPA which contains tons of themes and icon sets for previous Ubuntu versions and seems to be inactive since October 2018.
I'd like just to invite you to consider to package the most recent, mature and beautiful of them for Debian. Of course, some if them would need to be updated according to their OpenDesktop sources found in
https://www.gnome-look.org/For instance there's FlatRemix (both GTK/Gnome Shell and icons) by Dani Ruiz who also has his own PPA for Ubuntu. I think it should be easier for you starting from PPA. Also Zuki themes are mature and Nordic is very trendy at the moment and in current active development.
Best regards
Jessica