That's the whole point.
And the husband --- her one-and-only husband ---has to be faithful, too. He either has to be reconciled to her, or remain single and celibate out of faithfulness to her. At least, that's what the Christian Scriptures teach.
Tbis is actually enlightening to look up, if you want to get it from Jesus' perspective:
See Matthew 5:32, Matthew 19:9, Mark 10:11, Mark 10:12, Luke 15:18.
No divorce. And if you remarry, it's adultery.
This, then, became the practice of the early Church:
1 Corinthians 7:11-13
"But even if she does depart, let her remain unmarried or be reconciled to her husband. And a husband is not to divorce his wife."
That's good advice...But it's not the law...We are not under the law...But why don't you reference the rest of the chapter instead of just cherry picking a verse that 'appears', on its own, to bolster your opinion...