Why are Americans so afraid of an age gap?

Hi, I’m European, and I can’t help but notice how “terrified” Americans seem to be about dating someone even slightly older or younger than them. I lived in the America for 2 years, and I remember people being shocked when I mentioned something like, “My friend’s boyfriend is 7 years older than her...” I feel like the idea of completely avoiding even small age gaps has been implanted into newer generations’ minds.

I also come across lots of videos of American people on different social media addressing stuff like "Oh I have a crush on this person but I could never date them because they're 32 and I'm 27."

Like here in Europe, age gaps of up to 10-12 years maximum, are generally seen as normal and not something unusual or weird or anything like that.

Also, just to clarify, I am obviously not talking about minors, or stuff like that. I'm talking about relationships between consenting adults ONLY.

Edit: Clarified to avoid misunderstandings.