I don’t think it’s a coincedence that out of the Linux DE ecosystems, GNOME has probably the biggest presence in little third-party utilities made to match the environment. The DE itself is quite flawed in my opinion, but its consistent and opinionated design system catches the eyes of devs and would-be devs and motivates them to build things.
A similar effect I believe is what’s been largely responsible for the healthy botique indieware scene on macOS too.