This is inspired by an older thread called "Get your aging parents to downsize asap if they are still in their single family home." https://www.agingcare.com/discussions/how-to-get-your-parents-to-downsize-195854.htm
We've just held a Celebration of Life for my late mother. It fell to me to sort through the large cardboard box of memorabilia she had saved through many years and several moves. It was a touching task. It was bitter-sweet and I don't begrudge doing it. The pictures were a treasure. Some of them raised questions. Who is she with in this picture? What year was this? Why did she keep this -- what did it mean to her?
Going through their memory stashes with your parents while they can still answer your questions would be, in my opinion, a very worthwhile activity.
And organizing/purging/sorting and especially LABELING your own photos and keepsakes would be just as worthwhile for your descendants as downsizing your belongings. If push came to push they could hire a professional to handle your tea cups and rocking chairs and hooked rugs. But only you can provide context and identification to things you've kept for sentiment.
If they/you have loose hardcopy photos, label each on the back with a soft blue pencil made for the purpose (so as not to mar the front.) Sort them into boxes or envelopes by topic/year.
If they/you have electronic photos, sort them into folders by topic/year. (E.g. 1997 Garden Party, 2008 Picnics, 2011 Fourth of July) Identify the subject in the file name (Patty.Jo.Marcy 2012) If you have time and inclination, save only the best of the near-duplicates. Delete the blurry and unrecognizable.
A well-edited and organized set of memorabilia will be a blessing for descendants after you are gone!