https://bugs.winehq.org/show_bug.cgi?id=56014
--- Comment #2 from m1m1k4tz m1m1k4tz@protonmail.com --- (In reply to alexandros.frantzis from comment #1)
The Steam application (like many store apps) use CEF, which requires cross-process rendering. We don't support that yet in the Wayland driver.
Thanks for letting me know. There used to be an option to launch steam without the browser but it got depreciated so rip