I live in the Philippines. A foreigner shouldn't judge a Filipina's reasons for marrying an older foreigner until they have spent time with Filipino males. While a few are successful, 99% of them aren't capable of providing financially without severe hardship. A woman's choices narrow even further for upward mobility when we add rampant lack of education and provincial poverty.
Moreover, according to statistics, it's human nature to be attracted to financial security, which is a female's highest priority when searching for a mate. Security is just one of many attractions, such as beauty, we have when looking for a mate. Even in the wealthy US, most women will bypass a good-looking, charming man because he works a low-paying blue-collar job. As far as the age difference, historically, it's not that weird for a marital age difference of 20 years between sexes.
I am married to a Filipina 17 years younger than me. I met her in my early 50's and her middle 30's. There is no assumptive prostitution arrangement as suggested by other commenters. I met her while researching an article I was developing for Medium. We didn't even know what each other looked like when we first started dialoguing. She is my cliche soulmate and best friend and has stuck to me like glue through thick and thin. I love our more traditional marital roles that have nothing to do with repressing women. My experience and research points toward most Filipinas being fantastic marriage partners.
I agree that other than for companionship, seeing an early twenties woman with a 65-year-old or older white male is weird and wreaks a scam or usury. Unless the guy is an idiot, he knows it, and the two play their little game. Who's to judge if they both get what they want.
Of course, many Filipinas on dating websites are predator scammers playing off men's fantasies. There are even men pretending to be women draining men's pocketbooks, so buyer beware. But a sincere Filipina is a beautiful and loyal joy to have as a wife, age difference or not.