It depends on the threshold for consent, for me. If 'enthusiastic' consent is where the bar is set, as it is for many, an example of real life dubcon that is acceptable (at least to me) is willing obligatory sex - a partner who is not interested on their own engaging in sex because their other half wants it. In terms of fic, I love dubcon for the reasons you described and can only read/stomach certain kinds of noncon without trauma resurfacing (though it can be healing at other times)