This actually seems like it would be pretty good on something like the Librem 5! I like the idea of a tiling-esque window manager with this level of flexibility, especially on a phone. The launcher/sidebar/fitting/pinning/minimization features seem like an improvement over existing touch interfaces, especially on linux.
I don't think I would abandon my i3 setup for something like this for work, but I could see myself happily using something like this in a more casual setting. I hope that some of these ideas see the light of day with an actual implementation.
Our gnome-shell plugin https://github.com/paperwm/PaperWM implements a similar tiling mechanism. Although we allow mixing tiled and floating windows.
Things like "minimize" and "pin" are on the road map.