[kaba0]

Proper security is layered. Wayland is like a steel-framed door, while X is like having a hole for the door. Of course not even the steel door worth anything if you don’t have windows in place, but you can’t even begin to secure your place without a door.

X simply can’t separate different applications inputs and display outputs, unless you go full on nested X servers, while wayland solves this aspect splendidly.

Of course it is only a single step into the correct direction, you still need sandboxing and the like, but just sandboxing wouldn’t have been enough for X.