I don't know about charity coming to get everything for you, they are not willing to accept any toy donation these days and likely won't take anything they cannot sell for revenue.
I have been getting rid of stuff lately and the best thing I have tried is Facebook Market Place. Take a photo of everything and post them as free, and you will get way more people interested than spending money at Goodwill or Salvation Army. The good thing is they will come and take it and they will be used (people tend not to drive somewhere to pick up something they don't want). Since most charity donations end up in scrap instead of people in need, I like to just post free stuff online instead.
Since I am not getting cash, I usually leave my stuff at the street corner before people arrive and tell them it is in a bag or box for them to pick up. Most of the people would get there on time, some don't and then I will give it to someone else.
Charity is not in the junk removal business, they don't like the "take everything or nothing" deal, as some of the items can be hazmat and would cost them money or liability to deal with later. If you don't want it complicate just pay a junk removal company to take everything and promise to recycle or donate as much as they can. They charge by weight or volume, even the ones they will donate later they will charge you.
