Your team’s carry has to be 17 or 18 years old prodigy.
Ana TI wins at age 18 and 19
Yatoro TI wins at age 18 and 20
As the King Sumail himself said that on OG/Gorgc TI cast
TI is all about your carry, no matter how good you are if your carry don’t perform you are not going to win
Matumbaman won TI at age 22.
Skiter at age 24.
Fear at age 27.
Ame one of the best carries of all time did not win TI but got his best TI placing and Major wins at age 21-25.
I personally think that as long as a pos 1 or 2 is still focus on DotA they can excel even at late 20s or early 30s.
It just so happen that these 2 time TI carries were young when they won but if we consider major winners and other top placers on recent TIs it doesn’t always need to be teenagers.