Truth be told Linux should become the de-facto desktop. I like that you specifically mention i3. I think there is a strong use case for a Arch-like Linux distro that has an open architecture for building the entire distro from source into container images automatically. It would also allow desktops to be managed from a cluster manager like K8S. At first I thought packages should go with static binaries for packaging, but then quickly realized that they can use dependency containers and what not to dynamically include libraries with multiple version requirements if necessary, but still allowing for dynamic updates too.
Using container permissions also give you much of the permission structure you'd be looking for in your OS, much like a mobile device. I'm honestly surprised someone hasn't put in the development efforts to create a truly modern distro like Arch in containers for desktop and mobile. I think Purism is working with wlroots for Wayland. I'm looking forward to trying this with SwayWM if I can find the time, money and partners to help me with it.
Also, check out Simula for some AR/VR concepts: