An easy modified Desktop Environment written in Python was one of the goals of the "One Laptop per Child" project. They succeeded[1], it's now separate from the hardware and can run on anything from your phone, raspberry pi, regular computer and the OLPC-machines.
(Another goal was better sandboxing bitween apps. Their project was called Bitfrost and was in many ways the first step towards flatpak that we use today)
(Another goal was better sandboxing bitween apps. Their project was called Bitfrost and was in many ways the first step towards flatpak that we use today)
[1]: https://www.sugarlabs.org/