This is pretty significantly false in my experience.
I've had one LTR that cheated on me, and it destroyed her life. She knew that it would. Granted, I was not entirely in the alpha zone at the time, but I wasn't a full-on beta bitch, either.
We lived together and were basically 50/50 on essential finances, but without me there was no way she could even hope to maintain her lifestyle since I made three times as much as her. She normally would have had her father to fall back on for short-term financial support while she got a new place, but when he found out she cheated on me and was trying to kick me out of a house she couldn't afford, her own father disowned her in the resultant backlash.
The guy she cheated with lied to her, claiming he had at least a decent employment background/income potential, but it turns out he is in his mid thirties and has never had anything better than a minimum wage, entry level job and has been unemployed and mooching off his grandparents for seven years. When she found out about this lie, she dumped him for a total of 4 days while she begged me to come back (ha!) before she turned back to him.
The guy was exceptionally low-quality - had no real friends, no money, was overweight and unattractive but was a textbook Machiavellian personality and she was gullible as fuck.
When I left, she had $15k in savings and no debt, and the last time I talked her (six months later), her savings were 100% gone and her credit cards were maxed out. She actually asked me for money.
My TL;DR here is that women will cheat, and they absolutely do not think it through or perform any sort of tangible cost-benefit analysis.