Am i an asshole for wanting to take my boyfriends dog to the shelter?

Back story..

So me and my boyfriend work a lot. I work a fulltime job and he works multiple jobs, well a few months ago, i found a stray puppy in our yard. She was skin and bones. We already have 4 cats and 2 large breed dogs, so the original plan was to care for her until she got healthier then rehome her. Well my boyfriend got attached and decided he wanted to keep her. I was hesitant, because we work so much i knew we wouldn't have time to properly train a new puppy, and i was worried that he wouldn't care for her and all the responsibilities of her care would fall on me. (I already take care of all 6 of our other pets by myself) but he insisted that he would handle all her care and training so i reluctantly agreed.

Fast forward, his dog is now roughly 9 to 10 months old and she is a complete nightmare. He spends little to no time with her, and has left me to care for her. She destroys everything, every day i wake up to something new she has chewed up. I've had to clean up a huge mess every single day. Even when i pickup and put things out of her reach and try to redirect her with things that she can chew on, she climbs up onto my counters and tables and destroys everything. Im starting to hate her. I've told him several times that if he's not going to take the time for her that she deserves that he needs to give her to someone who does have the time. Its unfair to her really and a bit unfair to me as its his dog but i have to care for her after i explicitly said i did not have the extra time or energy to train a puppy.

His response was to say "shes just a puppy". Which is stupid to me because i started training my dogs from the moment i got them and they are very well behaved, never causing any issues. And dogs arent kids, they're dogs who have to be trained or you get nightmare animals 🤦‍♀️

Im frustrated and sick of dealing with it. I've been preaching for months that he needs to care for his own animals and spend time with her and he doesnt. I've even threatened to give her away if he doesn't take responsibility for her, and nothing has changed. So am i being an asshole for wanting to give her to someone who would take the time to be with her like she deserves?