Would guys view it as a red flag if I have no friends?

I had plenty of friends back in my small town back in Texas. I had been living in San Francisco for 4 years and haven’t been able to make a single friend here because the only way to make friends in a big city is to have outdoor hobbies or attend social events. I’m not interested in either because I’m super shy and quiet. It’s so hard to make friends here unless you’re a social person. I’m too scared to go on dating apps because I don’t want the local guys to think I’m a red flag or a friendless loser.