A few years ago our family initiated the 'Secret Santa' gift system for buying for adults and we have a limit of £50.00 each. This means that we only buy one gift and the recipient has no idea who bought it. This makes unwrapping gifts on Xmas day itself quite interesting and fun. There is still a small element of surprise.
We have a 'Chief Elf' (eldest granddaughter) who does the draw and pings a message over advising who one should buy for etc.
The grandchildren are excluded from this and are all bought gifts by their parents, grandparents, aunties and uncles (and now, even each other), so they still do quite well!
Husbands and wives also buy for each other although we can usually never think of anything we neither want or need so have to look a bit sheepish as the other couples unwrap beautiful gifts.
As my husband once bought me an ironing board for my birthday and a bag of pearl barley for our thirtieth wedding anniversary, you may understand why I am quite pleased that he doesn't have capacity* to choose and buy a gift for me!
*and no, he is not impaired in any diagnostically relevant way!! Just, 'a man'!