What else do you need?
You install, log into steam and play games. The age of modpatching custom kernels for low latency or hardware hacks is gone. The kernel already das what it takes to outperform windows on gaming. It's all on the user space now to bring convenience and ease of use.
The package distribution model was never popular with users. It was perfect for sys admins. But people don't want to manage a system, they want to use their device. Image based containerized OS and software distribution makes more sense for end users who have no interest on troubleshooting a pacbage dependency conflict.