

Proton is really meant to work through steam, UMU is meant to replicate how reliably games run through steam+proton without steam. There’s a reason that heroic and all the other game launchers are switching to UMU as the default for running games.
My basic understanding is that, in addition to proton, steam provides a set of Linux runtimes, to make sure that the converted system calls from proton always match up with the correct standardized runtimes on the Linux system, regardless of distro. They also provide winetricks/protontricks as needed for games. There’s also some system variables passed to tell proton/etc that the game is running through steam and has this setup. Finally steam distributes shader caches, which both improve performance, and bypass proprietary video codecs by replacing them with open source friendly video files.
UMU is basically replicating all of this except the shader/media distribution, hopefully allowing games to run as reliably outside of steam as they do inside of it.






Heroic is a great option, and will likely remain most people’s preferred way to play Epic games on Linux/SteamOS. After all, a lot of windows users prefer heroic there as well due to the bloat/slowness of the official Epic launcher.
That said, official support is always good. It both represents that Linux is growing and a viable alternative to windows, guarantees better support from games on the platform in the future, and pressures other companies to also support Linux.
Basically this (and GoG adding support) are big deals, even if it’s not because we really needed their official support to have a good way to play their games.