Right now it's a PoC (proof of concept, a rough implementation of an idea), to emulate launching games from other stores as if they were launched from steam using proton.

What this could be used for is to create a new Linux launcher, where you setup proton once, and launch all games using this launcher.

This simplifies usage for you as the end user, since you would only need to install the launcher, and it sets up ProtonGE, and you're done. It also enables simple Proton usage for other games (Epic, Lutris, whatever).

Additionally it helps unifying development. Windows games under Linux have a lot of moving parts: there's Proton as a compatibility layer. There's integration between steam, proton and your system (sniper/vessel). There's protonfixes which is game specific changes in proton. Each of which itself consists of components and stuff I've missed. In short, it's complicated. Unifying all this components with one tool, with one battle tested installation and compatibility and with a single source of truth in development could be another big step in Linux gaming.

TLDR - potentially a new launcher for games under the Linux, enabling any game to be played using proton, when supported, not only steam games.