Not sure if this is a state everyone can reach, or would want to, but I'm quite sure it's attainable for lots of people.
(Aside, I have some friends who are bad at asserting themselves in the ways I was talking about, but about, like, everything. They'll say "I want X", but they'll feel they have to provide a good reason for it to be taken seriously, e.g. "I want to eat dinner early tonight because it messes up my sleep when we eat late".
(You can imagine the kind of relationships (family or friends or romantic) they might have had in their lives which trained them to act this way...)
So they act like they have to give a sufficiently good reason for their preferences to be taken seriously.... which is, IMO, the degraded state I'm talking about.
In a respectful relationship, the fact that you want something IS a reason to do it; you don't have to provide a logically adequate reason to get what you want as well. And if two people's desires are incompatible, both will happily compromise to find a way to make them compatible again.)