https://github.com/GloriousEggroll/ULWGL
From the github:
WHAT DOES THIS MEAN FOR OTHER LAUNCHERS (lutris/bottles/heroic/legendary,etc):
- everyone can use + contribute to the same protonfixes, no more managing individual install scripts per launcher
- everyone can run their games through proton just like a native steam game
- no steam or steam binaries required
- a unified online database of game fixes (protonfixes)
Someone else already explained the licenses, but to your second point, yes, nothing stops any other launcher from using proton, which is what all the other open source launchers do. And yes, no one "needs" this project, just like we don't "need" any standards for anything, but it could make things a lot cleaner and easier to support.