Honestly, I can kind of see what she means in a way - instead of falling in love with an affair partner, these husbands are meeting a particular sexual desire with someone transactionally, with defined parameters and no emotional connection to 'take away' from the marriage.
I've heard the argument made by a sex worker, and superficially it makes sense that someone living in the terrible hell of a marriage without intimacy they need, who would otherwise not consider an affair, is able to get that one component without needing to form any emotional connection outside the relationship.
The truth however is different. There is exposure to disease, and there is the way it defiles the relationship and family and soul to turn it all into a lie. Every kiss for your spouse, every moment with your kids, every year you grow old together, all sullied.
Not a favour in my opinion.