Font Downloader is a simple to use and adaptive GTK application that allows you to search and install fonts directly from Google Fonts.
Find it on Flathub: https://flathub.org/apps/details/org.gustavoperedo.FontDownloader
@paoloredaelli @gnome "font manager" fills that role for me, for installed fonts anyway! Flathub link (since above is flathub too): https://flathub.org/apps/details/org.gnome.FontManager .
For people who care about, support, or build Free, Libre, and Open Source Software (FLOSS).