Sorry about your wife. It sucks to go through with that. Let me give you the other side of the story.
My father is slowly succumbing due to frontal-temporal dementia. In the span of 10 years he's gone from a social, independent man to a an extremely mentally challenged man with cognitive capacity of a 1 year old child. He is prone to ever increasing psychotic fits of violence and actual epileptic fits. Medication helps but they bring their own challenging behaviors. His body is still physically strong. He can still run if he so pleases. He has no problems getting into bed and standing but he needs help 24/7 with every single daily task. He cannot use the bathroom well so several times a day there is pee and poo to clean either from a diaper or the floor. Giving him a bath or shower is a delicate dance that 9/10 times is no problem but once in a while he can come out swinging. He has physically struck in the face, bit, headbutted, scratched and kicked all of us during these episodes.
My mom alone cannot deal with him. I, have to sometimes physically restrain him using quite a bit of my strength, in a way that doesn't hurt him. I try to read as much as I can about how to approach him as a patient and learn what triggers him, what scares him, how to calm and distract as an attempt to de-escalate these things. There were times when violent events happened multiple times a day, every day for weeks regardless of what the dosages of his meds were. He is also prone to insomnia and sometimes wakes up at 2-3am and refuses to go to bed disrupting my mother and I's sleep multiple times a week.
On top of that, he is completely vulnerable and helpless just like a 1 year old child. It's heartbreaking to have to deal with him when he gets violent. When he gets a full seizure and falls is always a traumatic thing for us. After talks with his neurologist, psychologist etc we put him in a care home.
It's callous to say, but honestly having him at home was simply not worth the cost to the entire rest of the family. As cold as it sounds, I stand by our decision to get him out of our daily lives. Mine and my mom's mental and physical health has taken a huge in the last 5 years. My career has essentially stopped since our whole day pretty much revolved around his care.
Your comment comes off as a bit too one-sided IMO. I know when my mom and I were at our wits end, she on the verge of a mental breakdown, I watching her slowly unwind, felt like a terrible person for even considering putting my father in a care home when I read comments like yours. My story is neither extreme nor unique. Having reached out to other people caring for dementia patients, caretaker fatigue is a real thing. Dealing with violence is common.
Not everyone who considers putting a loved one in a care home is a terrible person.