I do find all this interesting. It seems very clear cut to me, but of course people have different views
To pick up on this, I wouldn’t want my DH to relate or behave towards me as if I’m interchangeable with one of his male friends or something. I know I’m equal to men, just not the same.
I wouldn't want DH to treat me as interchangeable with one of his male friends or one of his female friends (he has lots of both) I'm not his friend (or not only that!)
I do expect my male friends to treat me (and other female friends) in a broadly similar way to their male friends, I expect my work colleagues to treat me broadly the same as male colleagues, I expect my parents to treat me in broadly similar ways to DB (or at least for those differences to be based on our personality and circumstance, not gender)
Similarly with some of your examples, it's about specific situations in which someone might have skills/attributes which means it makes sense for them to do something.
E.g.
If we were at home to an intruder I would not expect DH to go downstairs and put himself at risk. But as he's over six foot and I'm 5"3 it would make sense if he moved furniture to barricade the door so the intruder didn't get in and I climbed out the window to get help (or whatever!) But that's common sense, not chivalry.
And of course I don't claim that removing chivalry will solve the equality problem (I don't know enough about Japanese culture to comment on the situation there) but I do want to challenge sexism in all its forms, even when it seems to benefit women. Although as I and pp have said, I don't think that's the whole picture.
Also, rather late reply to @PBo83 to say thank you for your respectful reply to my post- we will agree to differ but nice to have friendly debate on the internet!