Maybe the quality of the services improve to a level where you would want to buy them in a non-corrupt, non-inflationary monetary system.
Discussion
I have several services I pay for that cost me thousands a year but I could not justify paying them in full up front.
Subscriptions exist for reasons other than extracting money continuously… like for actual affordability reasons
A money that appreciates so fast that you’d want to pay a full sum up front is not good money. Subscriptions will exist regardless of service quality.