It seems to me that it would be easy enough to do experiments (maybe a month long) to find out how you're affected. I doubt that the answer is the same for everyone, and it might not be the same for most people at all times.

If there's a quickly changing situation at work or at home, this might mean that you want all your email in one queue.

If work or home is resulting in highly fraught email, you might want the non-fraught one as a refuge.

And you might have privacy concerns which mean that you absolutely don't want the both of them in one queue.