When should you stop exchanging Christmas gifts with adult siblings?

So our family is all getting up there in age, siblings and siblings in laws are all married, new babies keep arriving. I may sound like Ebenezer Scrooge, but when is a good time to stop exchanging gifts between adult siblings? Now that we have kids I feel we should just exchange between them, but I let my sister decide and she still wants to exchange gifts between us. I feel bad but now that I’m an adult, if I want something I just buy it. Plus, I always feel stingy trying to bring up what the $ limit should be, bc I want things to be even. I feel the same for my Hub’s side of the family but no one has said anything and I certainly don’t want to be the ‘curmudgeon’ of the family. Your thoughts?