There's a chance that voting Democrats will prefer Buttigieg over Newsom in the primary, because of B's language skills and relative humility compared to N -- but the rest of the country is not going to vote for a gay guy with language skills, just as they wouldn't vote for a Latina with language skills (e.g., AOC).
And then there's the other matter: that Mayor Pete didn't come out until he was 37, because some political opponent was about to out him anyway. I came out in my early 20s, and I'm older than Mayor Pete.