'Someone had to win' isn't a full explanation on its own, no. (If it were, it would be a fully general explanation schema; 'something had to happen', for example, can explain any event.) Rather, 'someone had to win' is an explanation for an unlikely victory when you posit a large sample space. In most cases, selection bias will also play a role in the explanation -- it will account for the prima facie salience or interestingness of the event.

If selection bias and the size of the sample space don't help make you any less confused about why some X happened to you, then revisiting 'someone had to X' shouldn't alleviate your confusion.