This question just came to me while I was buying a subway pass. It’s priced very well, provides a very good service, doesn’t suffer from enshittification, and its price increases very rarely.
What are some other services which people don’t mind subscribing to?
Even software that does not require back-end resources has a cost if it’s actively supported and/or receiving new features. These hours the developers put it are often unpaid when talking about open source, but it’s not something anyone should take for granted.