It really is! I explain it to every couple I marry. When I celebrate Eucharist, I do the action of confecting it. In Penance, I give absolution. But Marriage is unique in that I don’t “do” anything save for serve as a witness; it’s the couple doing.
Even more interesting historically. For a time, the Church struggled with the reality of the Sacramental bond formed in private, between the couple, with no witnesses. You can imagine the problems this caused, so the Church established the fact that this is a public sacrament, to be done in front of the Church with witnesses. Even the “Wedding Mass” is a young concept, as the most traditional mode was to get married at the entrance/stairs of the church building in front of the entire town in a simple ceremony, in keeping with the Church’s determination that it was in fact a public event.