Gale didn’t just not end up with Katniss though he got completely cut out of her life. They were best friends and depended on each other to keep their families alive.
I don’t care if you don’t like Gale or what but don’t tell me that’s not fucking tragic as hell. Especially since we never find out what happened to Gale. His story just stops after we find out he goes to live in Two, and as far as we know he never gets to see his best friend again.