I'm not sure about all traditions being peer pressure by dead people. There are a lot of posts on GN about things like sending cards, which are, to me, 'traditions' started by commercial companies and continued because of emotional blackmail.
Some traditions, such as eating turkey at Christmas, are made to be adapted to differing likes and dislikes, so people will make nut roasts, order in curry or have beef if they prefer, but the family dinner tradition generally remains because people want to do it. Crackers, hats and whether or not to watch The Queen are all adapted to individual families within the overall pick and mix of Christmas 'traditions'.
The Changing of the Guard, or the State Opening Of Parliament, and similar State traditions, on the other hand, are absolutely remnants of an old world order with white men at the top.