This commentary is by Rustam Sengupta, the founder and CEO of Tuktu, a community-powered care platform. He lives in Burlington and supports his father, who has dementia. Last month I met Margaret. That’s not her real name, but her situation is real. She came to a small community gathering I host around Vermont to facilitate conversations about care and what it means to support each other here. She is 78 and lives alone in a farmhouse outside Mon…