Walled gardens are popular due to comfort & financial viability, It has nothing to do with security. People will still use Android or iOS even if you build a s

Walled gardens are popular due to comfort & financial viability, It has nothing to do with security. People will still use Android or iOS even if you build a state of art mobile OS based on SeL4 completely written in Rust & ATS, with more features and customizability than Android or iOS. Because it doesn't come preinstalled on their devices, and does not have popular apps. I am afraid walled gardens are logical conclusion of the field, for the things industry tends to optimize.