>"Unexamined legacy subscriptions paid without a thought," is another way of saying, "Has too much money."
I constantly see ads for services like RocketMoney which helps people find and cancel subscriptions. I could arguably be in the "too much money" camp, but I couldn't imagine seeing an unknown/unused charge on my credit card bill and not immediately cancelling it. Nonetheless, RocketMoney seems like a widely used product.
Doesn't help that sometimes the charges are coded like *TST VENDOR ACCT #1541*
I don't go over my bill every month but get a notification upon every new charge, and sometimes the only way I know that a charge I just put on at a store is the same one I got a notification for is because the charge amount is some relatively unique number.
A surprising number of people clearly simply do not look at their credit card bills.