As of GNOME 45, this will also allow Steam to be opened from the background via this Portal - I'm guessing this would also mostly replace the entire point of the Steam tray icon, combined with the right-click menu of the desktop file.
It would be fantastic to see this get implemented, as we currently have to rely on unsupported legacy tray icon functionality that's only enabled via plugin, on Gnome.
Historical context:
This FreeDesktop specification is already implemented by many desktop environments (if this wiki page is any indication), including KDE, Deepin, Cinnamon, GNOME, elementaryOS/Pantheon, and possibly others.
My general impression is that this would be the more future-proof, sustainable and natively-integrated way to handle the traditional "minimize to system tray icon" usecase in the long term, particularly for applications running inside Flatpak, and as the Linux desktop is generally moving towards immutable OSes and Wayland, complemented with Flatpak for apps. It lets the app officially keep running in the background without a visible window, without its process getting killed by the Flatpak sandbox for security reasons.
It also lets you do things like specifying the reason why it is running, using the SetStatus function so the desktop environment UI can also expose this for the user. For example, Pika Backup says "Monitoring Backup Schedule", Shortwave says "Playing [the radio station name]", etc.
Your system information
Any modern Linux system that supports portals, and may not have tray icons.
Please describe your issue in as much detail as possible:
Steam does not support various portals - it contains support for some, like the FileChooser portal, but it's lacking on others. This is one of them, along with the DynamicLauncher portal.
This would allow Steam to better let the user when it's running in the background, and desktops to potentially better integrate it. Additionally, Steam relying on tray icons isn't the best UX. They're inconsistent, buggy, not compatible with a sandbox, and barely function as-is.
Steps for reproducing this issue:
This is not reproducible on the Steam Flatpak, as Flatpak knows when an app is running without a visible window - however, normally, this isn't the case, since Steam might be running outside of a sandbox.