I'm not him but realistically, its a mixture of popular blogs and churning credit card content on social media which is the name some people use for the practice of farming bonuses.
Credit score is impacted by the average age but tbh, I've gotten two mortgages while doing this and compared the numbers with my peers and it could be my situation is unusual but the "cost" was like .2% APR between those that don't churn in my RL group and those that do.
It has (in my experience with multiple mortgages) have a rate set by competent use of credit that does not lead you to have much debt but paying regularly in practice regardless of what the public credit score algo is telling people.
Credit score is impacted by the average age but tbh, I've gotten two mortgages while doing this and compared the numbers with my peers and it could be my situation is unusual but the "cost" was like .2% APR between those that don't churn in my RL group and those that do.
It has (in my experience with multiple mortgages) have a rate set by competent use of credit that does not lead you to have much debt but paying regularly in practice regardless of what the public credit score algo is telling people.