guy gets his house foreclosed in 2009.  He knows the bitter sting of foreclosure.  He is not an expert on the mortgage crisis and is not qualified to speak on it in a larger sense.
A slave is beaten in 1847.  He suffers under slavery.  He is not an expert in slavery and is not qualified as an expert in it in its larger historical context..
A young teen man enters a prison and is terrified of being raped.  He is not an expert in sexism or the culture that produces it.  He is one scared person who may have an interesting tale to tell, but it is just one tale, one set of feelings.
Feelings aren’t knowledge and personal narrative is not wisdom.  It will by its nature likely miss important connections and contexts.  To answer your question, no, I would not know more than a gay guy about homophobia, because I also just have one limited perspective.   Given just those two options, two individuals, the individual with personal experience might have a bit more to say about it.  But maybe not.  The gay guy might be a halfwit with no interest in learning, no ability to empathize or connect or understand what the hell is going on in the bigger picture.  Social identity does not mean the person has real knowledge.   Can we learn more about the mortgage crisis froma  guy who’s been through it.  Yes, maybe, a bit more, but we might learn even less.  He might be a moron.  He might blame all the wrong causes.  In fact, he probably will exhibit all kinds of biases.  One data point, obviously, one little tale in a sea of information.  Same for all individual experiences.
This disagreement we’re having though may point to a deeper issue, an issue concerning how men and women may be wired differently.  Women, it seems argue by way of feelings.  Feelings and connections may carry more weight than less personal data.