North Carolina is the only state that has lawsuits for alienation of affection.
In a recent case, Mistress Ordered to Pay $5.8 Million” to Wronged Wife. Apparently the rest of the USA regards these cases as ridiculously outmoded.
All 50 states have laws against interference with contracts. That is, if two parties have a contract and a third party persuades one of them to break the contract, then the other party to the contract can sue the third party for damages.
I often get junk mail from real estate agents, and there is always a disclaimer saying that it is not intended to interfere with any relationship that I might already have with an agent. That is to avoid a lawsuit for interference with contracts.
If marriage were considered a valid contract for the affections of the spouses, then there would be just as much reason for alienation-of-affection lawsuits as any other lawsuits for interfering with contracts. But here in California, adultery is legal, and the state cannot even explain in court that marriage law has a rational purpose.
There is a campaign to devalue and destroy marriage as it has been known for centuries. This is just one example.