The focus on the identity/group of the author, rather than the quality and accuracy of the material, causes self-censorship and reduces the breadth of material available for everyone to enjoy. It reduces how often people can actually represent foreign/minority/"other" groups in their writing. I think it is a wrong and harmful approach.
So, my personal experience of representation isn't about ethnicity. I'm an Ashkenazic Jew, and I'd be perfectly happy if I never saw anyone with my particular ethnic background in fiction ever again (not that this is likely).
But I have experienced its importance in other ways. I have Crohn's disease, diabetes, asthma, and a herniated disk in my back. These conditions are pretty well controlled now, but that wasn't true in my twenties. They could be extremely debilitating, and I recall thinking of myself as, essentially, less than human.
One of the things that really helped me through that time was the Vorkosigan series, by Lois McMaster Bujold. The series is a space opera with elements of military sci-fi, but rather then starring a physically capable space adventurer type, it features Miles Vorkosigan, who was born with physical deformities and can't even run without risking a broken bone. This is sometimes an
advantage to him, as the Bond villain-types he goes up against frequently underestimate him until it's too late. Seeing someone who had debilitating medical conditions saving the day actually helped restore my sense of self. Moreover, I would say that the series is very much
about the experience of being disabled, and that this is precisely why it worked for me.
Now Bujold does not, as far as I know, have any disabilities or debilitating chronic illnesses. Had someone told her she shouldn't write a story about the experience of someone who does, and she'd listened, I would have been denied one of the primary things that helped me get through that time.
I don't mean this as a blanket rejection of complaints about writers who appropriate other people's perspectives, by any means. A lot of those complaints are no doubt warranted, considering how easy it is for writers to fall back on stereotype. Nor do I think that most of the people bringing up these concerns categorically reject all works that cross cultural boundaries--most object to those that do it
badly, which is a lot of them because doing it well is difficult. But there
are some people calling for that kind of categorical rejection, and I too think that this would be very harmful.