Why do people look down on single women in their 30s?

Not sure if it’s just a cultural thing, because where I’m from if you’re over 25 and still unmarried you’re basically considered a “leftover”. This whole toxic standard is actually causing harm to lots of women. A lot of these woman ended up marrying any guy that is willing to marry them to avoid judgment. I have friends who are in their mid-late 30s who are single, and has no intention of ever getting married or have children. So why are people still looking down on these women?

Why do people look down on single women in their 30s?
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