An OS that ships without tools to make apps for it is not an Operating System but rather an Appliance System.
And, for those who will reply "but my disk space and all the bloat of a compiler onboard methodology" - well that'd be a next step: destroy the bloat.
I work with digitalisation in the public sector of Denmark, one of the most digitised countries in the world. We have thousands of employees and citizens who interact with our systems on a daily basis and when we benchmark them on what they want public sector software to be like they unanimously tell us they want it to be more like the iOS experience.
They simply don’t want technology to get in the way, and they don’t care that the price for this is ownership and freedom. For them the glory days won’t begin until they can get completely away from the operation systems and applications of “old”.
Imagine we had a compiler-on-board philosophy as well as a peer-to-peer-is-the-new-network purpose, and we built a new OS?
I personally think such a thing would be golden.
For purists, even just a web browser and a basic text editor is enough to write programs that can be run locally, and without Internet access. (Additional tooling/libraries still helps immensely though.)
Having (access to) a compiler is not the missing linchpin it once was.
I really liked Sugar OS[0], and its on-device access to the code running the OS on the device, and how hackable that made the resulting device.
All the other methods encourage bloat.
If this is enough to deter the glory days of computing, then just imagine having to deal with your first syntax error.