I sold family house and moved when I was 62 years old. Stayed in same area, but smaller house. At that time, I would have hated to live in a flat. I Loved this house and lavished work on it each year as I continued to work. When I moved In the I thought it would be my final home. But as the year passed I realised this could not be the case. What was wonderful in my sixties, became harder as I approached my eighties. By then, the staircase I happily ran up and down when I first moved in, became like climbing Everest each evening. I dislike stair lifts, and they really have limited use if only person in the property (Cannot end up heavy items on them unless one person at each end). The small garden which easily sorted in those ealry years had to be looked after by a regular gardener. Even those extra bedrooms (one of my first big jobs when I moved in, was to have one in the loft for grandchildren),, were unused as I found it hard work to have anyone staying with me.
At 79 I sold this and successfully moved 150 miles away to a flat in a sea -side town. NOT a retirement flat, but one which is central in the town, with buses stopping outside. Two bedrooms, large, airy Living/Dining room, en-suite (really an essential as we age), guest bathroom, kitchen, wide hallway, storage, and good sized enclose dbalcony, garage (even when I got rid of my car, this is so useful for mobility scooter and storage). I was then of an age when single storey living was/is wonderful.
Think it is difficult to totally 'future proof' in your sixties, usually your requirements then are totally different to what they will be should you live into your eighties and older.