I don't discount that the subscription model has merit, I only point out that the merit is for the developer not the customer. There is value in high entry costs as it keeps fly-by-night ideas from cluttering the app store and keeps those not interested in running a business out. Software shouldn't be released in beta form. It's not up to customers to build software - that's on the developer. The risk should be on the developer. We don't see the same risk in software that we see with other businesses. A baker might lose their house because their idea didn't end up turning a profit, but developers just wash their hands and try a new app.
The benefit to a one-time payment is that the developer needs to come up with another product. They can't make their business a calculator app, or an app that tracks packages already being tracked. Those are the sort of apps we see with subscriptions - low innovation AND low risk.
Instead, we see subscriptions that transfer risk to customers. That's not acceptable. If it's not a viable product release it free or find a way to turn it into one. Deliveries should have been a feature of Delicious Library, not its own app.
The only reason current software has more ongoing costs than previously is because current software is tied to a software as a service model. It's not intrinsic to the app itself. But the truth is, that most developers don't use subscriptions. That's what happened here. Heck, most don't use IAP either. We see it mostly with mobile apps because the cost of entry into these markets is so low. It's easy for a developer to come up with a feature and market it as an app. And since they don't have any other ideas, or interest in performing market research to find out how much their product is actually worth they just tack a subscription onto it. Honestly, they don't even care if it generates a lot of revenue, because they play the long game. Enough people over time will try the app and that will generate money - even if they don't provide any updates or add any features.