Thank you for raising this. Downsizing is a big topic all by itself and worth discussing.
I turn 74 this year, fortunately my wife and I are both in very good health. The issue is heightened for us as we don't have children. But we certainly have a lot of 'stuff'. We have different views on downsizing. My wife says we really must start now and she has started going through her books and giving them to charity shops.
I have 4000+ LP albums; I know that's a lot less than some. No I can't listen to them all but I want the option to do so. I enjoy being around all the accumulations of stuff over a lifetime and don't want to get rid of anything while I remain able to enjoy it OK I may soon round that final bend and be in the finishing straight; but when big bang time comes and I can't use it any more it can all go to auction sale.