I am a container evangelist, I find excuses to convert my jobs into Kubernetes workloads, and I frequently use the likes of podman for one off apps/processes and development. I use Flatpak frequently to isolate dependencies for the likes of Steam and Heroic.
I really wanted to like Bazzite or Bluefin, but I can’t deal with the overhead from the rpm os-tree updates. I would frequently notice hitches for my use case (sunshine streaming), and the hoops I had to do to configure Nvidia drivers (for it to then not work as good as other distros) was tiresome.
I went back to Arch (EndeavourOS), and I improved sunshine performance and had a driver that worked with less fiddling.
I’m saying all this because, while I’m glad to see any Linux distro grow, I hope it starts delivering what it says on the tin eventually without compromises that I experienced. Markering on it being immutable and container focused is true, but I dont see the benefit (aside from more stability which as others pointed out, is already stable is most cases)?. Right now, its a simple to configure (assuming most defaults work for your setup) distro that is finding a growing niche amongst some users (obviously by the data shown). And thats good enough for now at least.
Video games come to mind. You could probably figure out how to host a game server of their choice (think something like Minecraft) so him and his friends can play. Docker is a nice shortcut for that, and you also get to sprinkle in some networking knowledge too for opening ports and such.
If games are off the table, could try to figure out some hardware to interact with. Having some sort of robot that you can control with an API could be fun.
On the line with hardware, you can get a raspberry pi, and try to work with him to blink an LED via Scratch or Python. Then work to something even bigger.
If typing is a struggle you could do typeracer or something like that to figure out who can type faster.
You could build a basic website together with some CSS and HTML. Make like, a fan site for his favorite band (or whatever hes into). Maybe he wants to make something for his friends to see.
Or, ask them if there is something theyve wanted to know how it works…then build some sort of project using it.