The Role of Vows in Weddings

In every wedding I've ever seen been to or officiated there's something called vows and they say this is what I vow. Why do we say that at a wedding? You are married now. You may now kiss your bride. Like if I was like hey you guys should wait until you're married to kiss your well legalistic pastor like why are you doing that? But you can understand for a long time. Like in a time where we were actually better at marriage we did that. It's so crazy but it's just good to look at those things and be thoughtful.