Apparently buttons in buttonholes as a clothing fastener were not a thing until 1300 ce. Maybe that fact is false but, if true, it's crazy to me it took until 1300 ce to think of putting a "button" through a hole.

Maybe the issue is the defintion of "button" but still.

There's this non-serious book, "How to Invent Everything: A Survival Guide for the Stranded Time Traveler", which describes things you could introduce if you were beamed back in time. Things you could actually make and just took people to think of (vs like a smartphone that requires high-tech). "Buttons" was one of them.