This image says it all.
If a UFunction is marked as const (and also it’s returning a value) it will appear as pure, despite being specifically marked as callable.
The difference between pure and callable is important in cases when we want to write a complex and expensive function generating some result, which doesn’t modify the object.
A good example are components filtering large configuration data to convert some input into output.
There’s many other cases.
This issue might be small, almost cosmetic but it gets very annoying when programmers want to apply proper const-correctness in C++.
It means we need to write additional wrapper functions just to go around this problem.