That’s a logo, not a mascot. A logo is a mark that denotes a brand, the apple with the bite taken out for Apple, the footprint for GNOME, the stylized and colorized G for Google…
A mascot is a character that acts as a face and a voice for a brand. The gecko for Geico, Tony the Tiger for Frosted Flakes, Flo for Progressive.
Many brands looking to keep a serious, “sophisticated” brand aesthetic eschew mascots in favor of simple logos. GNOME follows suit with that trend. Nothing wrong with it, in fact I think it works quite well for them. If they were to adopt a mascot now it would be… Strange.