no, `const` means you can't modify the data through that `const` variable (excepting shenanigans), not that it's immutable. It can be rather confusing.
But that's the whole point, isn't it? I mean the selling point of these lifetime annotations is to allow developers to specify that data within a thread cannot be modified by the code running in that thread.
Isn't that exactly what const does?
Const doesn't solve aliasing.
It's one thing for an object to be immutable throughout is life cycle. That's immaterial to this discussion.
It's an entirely different thing that the same object cannot be changed within specific contexts.
If you want to ensure that a thread has read access to an object and it cannot be changed accidentally then passing a const reference to that object already ensures that. That's pretty much the whole point of const.
Const also has no bearing on lifetimes. Constexpr/consteval do, but those objects always have static lifetime so it's sort of irrelevant.