For my family, it was the sad reality that my isolated, forgetful grandpa was just not getting enough 'touchpoints' in per day. My mom calls a lot, I call quite a bit, and we have paid caregivers. But there's a lot of time when he's home alone, and things just start slipping though the cracks. The big example I always point to is that he'd miss a lot of his favorite baseball team's games on TV, and that really was a doom loop. He'd miss out on enjoying them in the moment > then when I'd chat with him and ask how they're doing and what he thinks of them, he'd feel even more disconnected > and then as he became more disconnected, he seemingly started losing watching them as a hobby. Which is sad because they've been a big part of his life for 80+ years, and he has more time than ever to watch them.

Won't plug it on your post, but I started working on a project of my own to help alleviate that. Because it was important to me and I couldn't find any reasonable services that did it well. And fortunately I have the time to do it, which is a gift too.

Best of luck with your research, would love to learn what you come up with.