Divorce was permitted in the OT, Jesus said it was because of our hardness of heart. It is not permitted in the NT.
Jesus also redefined adultry in the NT as if one committed it in the heart it was the same as doing the act.
No, adultery and desertion are two of the permitted reasons for divorce in the Bible. There is no commandment from Jesus, “Thou shalt never get divorced”. Jesus got angrier at the Pharisees in the NT than He ever got angry at someone caught in adultery or someone who had had more than one life partner.
A remarriage can of course be permitted if the spouse dies too.
Jesus knew we were ALL guilty of adultery in our hearts whenever we looked at someone not our spouse and desired that person, that’s why He made that broad statement. The wages of sin is death.