RetroArch is nice, but it’d be nice IMO to have a libretro frontend built for Lutris specifically. I understand RetroArch is the reference implementation of a libretro frontend, but I think UX could be improved somewhat by using a simplified interface for libretro cores and games. We don’t need to give up features like Cheats, Retro Achievements, and Shaders. The first two would be relatively simple to implement by my understanding, but the last would be more complex. Thankfully, there exists a library that reimplements RetroArch’s shader runtime, called Librashader. It’s written in Rust, and should be relatively easy to use from either Rust or C/C++ code.
The goals for this would be ease of configuration from within Lutris, and being simpler than RetroArch, since it doesn’t need to run on every computing device imaginable, it can be a lot simpler.