Yes, dementia destroys the person with it, but it also destroys everyone around them, usually as well. I write often about having my wife severely affected by Alzheimer's Dementia and Aphasia (early onset like Bruce Willis). I even wrote about moving from NJ to PA because family members told me they would help care for her, but they abandoned helping me in less than two months.
I attempted to explain this: I honor my commitment to care for my wife, and my caring alone began in 2017. Some of you empathize with me, not having a complete wife-husband relationship, some of you seem to believe that that is my problem to deal with (and it is). Not having friends to socialize with in this quaint, nice town with many positive attributes is like living on Mars with my wife, and we only take our spaceship out to go to healthcare. Groceries and supplies are brought to us with the supply ship from Earth about once a week. I experienced something last night disturbing; actually, two things.
1. I had a very difficult time getting her upstairs to wash and change her and into bed. And.
2. I enjoy many British television programs before I go to bed, and the one I have been watching lately is especially good: Bloodlands. Excellent story, mystery, suspense, and acting.
WHEN MY WIFE WAS NORMAL, WE WOULD TALK ABOUT THINGS LIKE THIS TV SHOW, BUT SHE IS OBLIVIOUS TO THEM NOW, AND I FEEL MORE ALONE THAN EVER. So yes, no intimacy is not good, but something as simple as discussing a TV show somehow seems even worse.
Link to the show: https://en.wikipedia.org/wiki/Bloodlands_(TV_series)