With the caveat that I am a straight writer as well...
I think we should write stories about LGBTQ+ characters. Representation matters, and I'm trying to do my part. The book I'm querying right now has a straight POV, but there is a very prominent gay couple. I have a WIP with multiple POVs; one of them I knew right off the bat she was gay, but another one as soon as I started getting to know her I realized she was bi. As a straight white woman, when I think about how I'm addressing race and sexuality in my writing, I go back to the one thing where I am on the under-represented side and I think about how I want to see just women in general presented in fiction. I'm fine with a man writing a female character, just so long as he does it well; I want more men to write strong, relatable female characters, especially in fantasy and sci-fi.
The one thing that we obviously can't do is claim #ownvoices, which is fine, and I know the other thing that I'm not going to do personally is write a story where one of the main focuses is a character dealing with their sexuality. I don't know that I could do a fair job on it, so I'm going to let other people who feel more compelled and who can do a better job tell those sorts of stories. Instead, I've acknowledged that I have the power to make my worlds however I want (since I write fantasy), so, for the WIP mentioned above, I purposefully decided to create a world where sexism, racism, and bias against sexuality/gender identity/etc. were just never a thing. So when two characters are talking, and one of them refers to his ex-husband, the reaction of the other character is about, oh, you were married before, not, oh, you're gay.
Obviously, I've put some thought into this topic. However, I want to do things right, so if there are writers here who are of the LGBTQ+ community who have a difference of opinion on what I've just said, please let me know, and I will listen. I'm trying my best to do my small part.