You think that's a thing other franchises LACK? WTF? (If you mean closure slightly less literal then no way in hell can you say that something like BG:ToB didn't provide closure.)
The emphasis is on the personalized part. Other games have done almost everything else with the storytelling, team customization, multiple endings and so on, but none can offer it all in one package of three consecutive games that build on each other and then it actually ends as well.