"The recommended usage is to colocate actions and states within the store" - why?

[jameshfisher]

In the official docs, I read

The recommended usage is to colocate actions and states within the store ... An alternative approach is to define actions at module level, external to the store. This has a few advantages ... This pattern doesn't offer any downsides ...

I therefore don't understand the recommendation. If the alternative has concrete advantages and no downsides, shouldn't it be the recommendation?

I then read:

... some may prefer colocating due to its encapsulated nature.

But what does this actually mean? What's the advantage that I'm not seeing? Isn't a JS module a perfectly fine encapsulation?

[dai-shi]

I think the wording is misleading or incorrect. Probably it should say "The typical usage is..."

I'm not exactly sure if "its encapsulated nature" is correct wording, but what it means is to define actions in the state.