It's beyond insane how, in the USA at least, you give someone a string of numbers and they basically get pull access to your money for what might as well be perpetuity. And that you have to use to a specific bank, Paypal, Apple Pay, etc. to have a system as simple as a list of entities authorized to bill you in the future. And the ability to terminate those permissions.
Just think how well most people would be served financially if everyone was receiving phone notifications when they were recur-rebilled. "$15 to 24-Hour Fitness" popups up on their homescreen. And they could cancel the permission. Or at least just think "hmm, what's that for? Ah, right, I do want to continue being billed."
It takes a lot of mental gymnastics and charity to imagine how this system wasn't expressly designed by and for the enrichment of grifters.
I think the majority instead contacted customer services to manually cancel it. Some also did a chargeback, which companies hate as it is expensive.
But in the end, there were so many sleepers that every time there was a plan to email all customers about an offer, or new service, it was always raised that it might make a lot of customers aware that they have the subscription, or check with their kids if they still need it, so sometimes the mailshots were filtered to active members, or just skipped all together etc. It was an uneasy balance of "don't touch", and never felt nice.
Last year I was contracted back to that company to help sunset the product I worked on years before, writing tools to notify and cancel all recurring payments. A huge chunk of customers was then sleepers that had not logged for 7-9 years. I do wonder how many were surprised when they got the cancellation email! :)