OhI know - we didn't downsize, and in fact the contrary- but in order to have space, we had to move to a cheap part of the world, out in the sticks... and yes, in Switzerland. Our large house here was half the price of the house we sold in the UK. But we had to spend 2 years sorting stuff and giving it away to Charity shops and via freecycle. A skip would have been much easier, but I just could not do it. We had to give up a garden I had spent 30+ years getting just perfect, and same for the house. I was hoping to sell to someone who would love it as we did, and keep improving it- but that was just not possible- and yes, it is heartbreaking. Although in our case it was a choice- whereas for my parents it was not. They just had to do it- as they neither had the energy to maintain the place, nor the finances. In their 70s they had to get rid of so much stuff that had been in the family for generations- no choice. As it happens, at their demise (we moved here partly to be here for them in their latter years, but got here just too late) we inherited all the stuff that was left ...
As said, 100s of 1000s of people who own their own houses have no choice but to downsize later in life - it is not something that just happens (or in fact, does not happen) in council housing.
In Leicester, the council built a lot of bungalows some years ago for older couples, with excellent support and infrastructure, and older people with extra and unneeded bedrooms were given the choice to move there, on the other side of town, as a group of friends that had brought up their children together. It worked very well indeed, and one of my friends was delighted to move away from noisy families and have a groundfloor bungalow well adapted for their needs. it can be done, if done properly - thus releasing larger homes with gardens for families.