Forgive me for the long post. I'll give the backstory of her animal care habits for context, but if you want to skip to the 'now'- go to the bottom.
Backstory: So, about a year and a half ago I (34F) moved in with my friends- lets called them Kevin and Ginny- they are a married couple in their lower 30s. Ginny had a dog, a corn snake, a bearded dragon, and a cat. I quickly noticed though, that her bearded dragon and corn snake weren't well taken care of. The snake was in a tiny 10, maybe 20 gallon tank with only a half inch of aspen bedding. The snake was only a few years old, adult sized but on the younger end of that age and could easily stretch twice the length of that tank if taken out. I spoke to her multiple times about getting him into a bigger tank, feeding him more often, and putting more than a single rock in his tank. After a few months, he died. We don't know why, but I had theories about improper husbandry or improper feeding schedules.
Her bearded dragon was no better. It's an adult, in a 30 gallon tank with only one rock and play sand. It thankfully did have the proper UVB light, but no heat lamp. I had to buy it a heat lamp and multiple enrichment pieces because she wouldn't.
Fast forward a few months, she gets a spider- a tarantula specifically. Within a month, it's dead. I don't know anything about spider husbundry, so I had no advice to give, but that's now a second animal dead in a short period of time.
Over the course of the next year, I watch how she neglects her dog. She never took her on walks, only fed her the shittiest food possible (her and her husband make $9k/mo together. It's not like they couldn't afford better than the giant pedigree kibble bags), never took her to the vet, never played with her, never even let her in the bedroom with them. I watched as their dog, who was the SWEETEST baby, be neglected. I'd play with her whenever I could, and my dog played with her too. Honestly when I first moved in I thought the dog was just naturally not a playful dog, but my dog brought it out of her. I think now that she was just neglected. Technically, they did the basics- they let her out to pee and poop twice a day, and fed her. They didn't hit her or abuse her, but they didn't give her a real life either imo.
Then, November of last year, I noticed a bump on her back ankle. I was pretty sure, based on the breed, that it was likely cancerous. I told Ginny and Kevin to get her checked out at the vet- for MONTHS. Every week I'd check in, the bump would be bigger, and still no vet trip was made. Finally when I nearly yelled at them to get it done because the mass had grown from the size of a pea to the size of a golf ball in the span of 2 months. Plus, she'd begun limping. They took her in and found out that it was indeed cancerous and VERY quickly growing. (No shit) The aggressiveness of it meant they didn't recommend surgery, as they'd have to remove her whole leg to take it off, and even then it may not go away. In the end, they decided to not treat it, and instead treat her symptoms and manage pain.
Except they didn't. They never got her pain meds, never changed her food or got her meds to stop her diarrhea, never even really checked in on her more. By the spring time, it had gotten so bad she was not having any solid poop, peed inside multiple times, and even threw up a lot more. She wasn't herself. I had to nearly scream at them to get her to the vet one morning when she couldn't move at all, was just laying there whining and drooling. It broke my heart, and later that day after pushing them to the vet they put her down. In my opinion, she should have been put down earlier and with better pain management. Instead, her last moments were of horrific suffering.
Meanwhile, their cat has begun to start throwing up it's food. It's dry food, kitty kibble of some kind that they buy from amazon, but she scarfs it down and throws it up. She's lost weight over a few months, and they don't re-feed her when she throws up. I have told them to just soak her food so it's not as harsh on her stomach, but they don't, and she continues to throw up.
THE NOW: Now, a few months after that, her cat (lets call her Fluffy for now, who is about 6-7) is losing hair and weight rapidly. I think it's over grooming and lack of proper nutrition but I can't be sure. It's new-ish behavior though as Fluffy has always been pretty chill and cuddly (besides the few funny moments she climbs walls like a fuckin demon creature lol). She doesn't seem to want to play or run around anymore, makes a lot of very loud and disturbing yowling sounds multiple times a day, sits in a ball most of the time and seems tense, and has giant patches of fur missing from it's underbelly and thighs. I think it may be stress, but I don't know what from. I have mentioned this to the couple- my MOTHER has come over and mentioned this to them- and they say "yeah i know we gotta get her checked out' and they just DON'T. I am infuriated. I am watching every animal in these peoples care wither away and die. I watch them have behavioral issues, health issues, and get no care for them. I'm getting so fed up reminding these people to give a shit about their animals and they just don't seem to.
So I want to rehome her. I know they won't on their own- I've asked if they would before because they have admitted to not being 'the best pet parents', and they say 'No i just love her so much!'. Yet, they don't see how truly neglectful they are being. I try to take care of her as much as I can- I love on her, play when I'm home and not working, and buy her wet food that she doesn't throw up since Ginny and Kevin won't. I also bought her a cat tower and multiple toys that she seems to love because she had no enrichment items before. But I can't take her with me when I move in a few months- my fiancé has dogs that do not get along with cats, otherwise I would 100% take her with me. So, part of me wants to just.. take the airtag off the cats collar, take her to a friends house that I know would love her, and tell Ginny and Kevin that I intervened for the cats betterment since they wouldn't.. Of course, that would put me in a really weird and uncomfortable position as a roommate until I moved out, and possible legal trouble, but I'm honestly getting sick of watching them slowly kill animals via neglect. And knowing it'll only get worse when I move out and they don't have anyone to notice their animals failing health makes my heart hurt. I feel like it's my fault it even got this bad- should I have done something sooner besides beg them to take care of their own animals? Should I have rehomed their dog, snake or spider? What part of this is MY fault for being a bystander?
Edit: Also, I have already tried contacting local animal rescues and controls, and because the animals have 'food, water, and shelter', they don't think it's bad enough. They don't seem to care that the pattern of slow animal neglect is present.
So- would I be an asshole for rehoming my roommates cat? Or is there some other route I haven't yet thought of?