because that's weird. that's not a situation most people would have.
the card they got as a kid would be a shitty card with a very high APR. any smart person would dump it and replace it with a better card.
long term credit card keeping also isn't that huge of an impact on your score. when i got to 10+ years on an account, it bumped it up by 10 points.
it's not an insane game. you clearly have no experience with it. it's mundane and boring stuff that most of us never ever think about outside of weirdos who are trying to maximize their score or people who churn cards for the 0 apr rates.