My experience is that there is a belligerent phase too, which might correlate with hallucinations. At one point I was driving 4 hours every week or two to get to my Mom and Dad’s house to help care for my dad with Parkinsons. The last 6 months or so before my dad died were at the time when my 55-year-old husband with dementia was in the hallucinatory phase so I had to watch carefully to see that he didn’t try to unlock the door and get out of the vehicle when he didn’t know who I was and was convinced I was kidnapping him.
The belligerance was such that at one point when he was in the pickup when my daughter and I were picking up a Marketplace item, he got out of the pickup and we spent the next 4 hours trying to get him back in the pickup so we could go home. Eventually a nice elderly lady came walking along, realized our situation, and chatted with him for a while and suggested that he get in the pickup - which he did without objection. He was just fine with her but not with us.
My husband was always kind and even during the belligerent phase wasn’t violent - for which I was extremely thankful. But when you mention people seeing things that aren’t there, that rings true, and I see so much of my husband’s behavior in Biden.
My sister had a double whammy - White Brain Matter disease, from a concussion years prior, which was destroying her brain plus Alzheimer's.....I cannot put into words her great suffering so I won't try. Enough that she not only would get very violent and hurt hospital staff , but so strong it took 4 aides to hold her down...she was in her 70's. I cried so much for her I didn't know I had so many tears....Cognitive diseases are just so rough, for caretakers as well as patients.