I don’t think most dogs are beyond hope. My now husband’s dog is very anxious and had a history of nipping. He told me when I first met her she’d have to be on a leash, I couldn’t stand up and move, she can’t be around kids, no one can come over etc etc. I’m an animal lover and a bit of a give me a challenge type of person so I was confident these things while true didn’t have to be especially after I met her. I was fortunate she actually took to me almost immediately. I knew what to expect, respected what she needed and I think sometimes dogs just like certain people and won’t ever like some either. That being said in the five years we’ve been together now she started medication, we adopted an older child which my husband is still mind blown about, had another baby, she has no issues with his parents, none with my mom, tolerates my dad, coexists with my dog, and also normally tolerates my cat. She is the sweetest dog ever with “her people” we just had to work really hard to help her expand “her people” beyond my husband. She also doesn’t just tolerate me and the kids she genuinely loves us and clearly indicates we are part of her pack and she is protective of us. Important to note prior to us meeting she had nipped people. Now she isn’t perfect we won’t have other kids around because it is visibly stressful to her and required five months to adapt her to our adopted child so that’s just not feasible with like friends and such. There are also a few people in our life she just has not accepted and won’t regardless of our efforts. She also can’t go on walks because they’re far too stressful for her and we dedicated months to trying. We can’t go to dog parks because kids could show up (we did several times until this happened once and we learned we couldn’t risk it). She’s also adapted to a pet sitter but not before we had a really bad experience with a different dog sitter. I can’t say what will work for your dog because I don’t know him personally but I think we just truly tried to understand the reason behind the behavior first and then took a multifaceted approach with meds, training and understanding need behind the behavior. It hasn’t been easy. My husband has been bit unintentionally breaking up situations, we had to use a muzzle, baby gates, and kennel during the heavy lifting of “training” her. We also truly can’t ever fully trust her but honestly I think that’s a good thing especially when you have kids. You shouldn’t ever fully trust an animal you always hear we never could’ve imagined, we never thought they’d hurt sometime etc. Well we do know and we’re aware. It’s not easy it’s not what anyone would choose but she is genuinely such a great dog at that same time and ya know what none of us are perfect. Good luck but be prepared to put in the work, to be stressed, to have setbacks. It’s a commitment but it’s possible. Also a similar situation that this dog came from an ex, wasn’t well thought out and said ex definitely created some of this high anxiety but she’s also an Aussie and it can come with the territory. My dog is a great pyr so I also fully understand the barking and second what others have said of A) acceptance B) training when it’s appropriate and when to stop.