Meowing indicates that its body still hasn't started shutting down because if it did, the cat wouldn't meow at all if it were in the critical stages. It could have gotten help. Besides, if it can meow, it can breathe, even if slightly.
Yeah...but...like if there was severe internal damage or (because of maggots) major infestation of parasites inside its body. Who knows? Could've been saved, maybe not. Vet bills are also pretty hefty now, and insurance is usually not practical.
Last February (February 17, 2013), I lost my dog that I've had almost my entire life. She was fifteen years old. The day we put her down, we had her in the laundry room and she was just sitting on her bed watching us through the gate. She would get up and stumble up to the gate and watch us move about the kitchen, then after a few minutes lay back down again. She didn't seem to be in much pain (she probably was, though, just quiet about it). She wasn't really eating or drinking anything. The month before (the same day Stan Musial died), she had had a seizure/stroke in the kitchen that rendered her mostly crippled. She'd stagger around in a limp, and sometimes would collapse on the floor unable to get up for a few minutes.
That afternoon came, and my parents said we were taking her to the vet. We probably wouldn't bring her back alive, they said. My mom picked her up and wrapped her in my favorite blanket from when I was little. I felt my throat getting really tight, and couldn't help thinking, "She is definitely going to make it longer. Why are we doing this now? I mean, she can still walk and breathe."
When we got there (an hour long drive that seemed like two minutes), we set her on the table. When we took the blanket off, we found blood on it. Turns out, she was bleeding from her intestinal tract. My whole family, and two of the dogs, stayed with her until she was gone. Afterwards, she lost some fluid through her nose. We think it was from her lungs.
Sure, she probably could have survived another couple of days, maybe even weeks (if she was really lucky, because she was hardly eating or drinking at all), but either way, she would have died in the end anyway. Those last few days would have been terrible for her too, as she was already very visibly in no quality of life on her last day.
I think with your cat, it would have been nearly the same way. The vet bills, if you're family had tried to save him, would have left a huge dent. Even then, if you're family couldn't have saved him, the money would all have been wasted. We all love our animals, but practicality comes in more with animals than humans.