@Siouxtse1 - I managed to (when were downsizing) give away , sofas chairs , curtains , other bits of furniture, lamps and a whole load of kitchen stuff to three or four people who were setting up home for the first time. Didn't worry about selling it - just happy it did a good job for someone.
I gave away a huge number of books to charity shops but they ended up saying we can't take any more books. I have a Kindle now - for day to day reading it just makes sense - I have my very favourite books on the shelf but no longer have the storage / bookshelves I had before. Have also given a lovely set of books to a friend of DS as he will cherish them .
I had a lovely artists easel - no room for it so gave it to the local primary school - they liked it , lots of clothes I gave to friends' daughters ( when they said they would like them - I did not force them on the poor Dd's )
I am not by any means an ecological evangelist - but I do not like waste. If something one cannot use can be used by someone else - well to me that is just great.
The thing is charity shops are often full so it genuinely can be hard to give things away - that said - if people try - great. Also - when I cleared out DPil's house - it was heartbreaking how much stuff they had just kept. A small example, in the attic they had toys for their GDCs still in the original wrapping - these were for young children and the DGCs were teenagers . When the chaps clearing the house out saw this , one of them said - could I take these for my grand kids I said Oh please do. The other clearance chap saw a set of sherry glasses in their original wrapping and said this will make a nice present for my sister may I have it . Yes please take it - anything that doesn't go to the tip please take it if it will be nice for someone else.
The experience of clearing out my DPil's house has made me so much more ruthless in getting rid of stuff - & recycle or sell or whatever right now. Don't leave it for your children to do. I have given away so much stuff , a few things I sold , but of everything , there is only one thing I regret , the rest I haven't thought about twice.
Those with huge storage available to them may think differently & be able to put things somewhere - I can't.
Anyway enough from me