The title says it all. Browsed Flathub and saw this fat warning label on the Steam Flatpak. Maybe not the best idea if you want to compete with Canoncial's Snapstore, but hey, what do I know 🤷
From Wikipedia, the free encyclopedia
Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.
Community icon by Alpár-Etele Méder, licensed under CC BY 3.0
You don’t have to open source everything to open source the client software that is expected to run on devices the software author doesn’t own or control (and so doesn’t care about or put in effort to protect)