I enjoyed this article and was impressed with how far the author got in each day's exploration. I always thought Plan9 should have had a comeback as part of the "Internet of Things" given its deep support for networking and its modest hardware requirements (it was designed in the 90s.)
The problem is drivers. They haven't kept up so far as I know and the list of supported hardware is short. Personally I'd love for that to change, but it isn't something I can do.
We even managed to get arm64 support on the Raspberry pi before Ubuntu. :)