Then, when you're 25, your daddy dies aged only 56 and after a rather brief period of mourning you get pushed into taking his job in a pompous ceremony. Now you're going to be doing this until you die. No retirement! I bet there were times where Lilibet just wanted to go to her room and cry.
I wouldn't have wanted her job for all the wealth and power that came with it.
[1] Well, you could make a big scandal about marrying an American divorcee, but that didn't go down too well for the last guy.
Queen Elizabeth could've just passed on the throne to her son any time she wanted to.