I'm not sure that's a trend, but a peculiarity of Redux/Baobab.
Without built in immutable data structures, I think this kind of paradigm will always be harder to work with in JS than smaller, distributed, mutable models.
It's not like OOP languages where the built-in data structures are built up from many layers of inheritance that all have to be made immutable. Where access is blocked at the language level (ex private/protected).
Immutabilit is not difficult in JS. It's just not immetiately intuitive unless you understand the value of comparison by reference.
The == vs === always seemed like a strange vestigial appendage of JS. With the recent trends, it's beginning to make a lot more sense.
Without built in immutable data structures, I think this kind of paradigm will always be harder to work with in JS than smaller, distributed, mutable models.