Add to it the subject of visas/PR and citizenship. In most cases, marriage to a national will give you the reason to be in the country and will qualify you for visas. In the EU, Japan, etc.There are some situations where marriage is a viable option, but the reasons are mostly utilitarian, such as furthering careers (see: celebrities and politicians), maintaining or expanding wealth (see: old money) or not having the time or the inclination to pursue hookups (see: Steve Jobs, Bill Gates, Zuckerberg, CEOs...)
But for the average schmuck? Nah. It isn't worth it most of the time.
Otherwise, unless you have a good job, you will just be on your own.
Also, in many countries that is the only way you will get to have sex with a virgin.