The more a think about it, the more a I come to the conclusion that we need a mixed computing paradigm.

For many tasks (probably most and certainly for most people) the iOS model is the best.

It is, however way too restrictive for a number of use cases. Prohibitively so.

Imagine two very different and isolated environments. Terminal, compilers, file managers in one, most other software in the other. With perhaps shared folders between them.