Apple willfully ignored 25+ years of commercial software distribution trial-and-error market experimentation and education.
Try Before You Buy won a long time ago, but for some inexplicable reason Apple seems to want to drag us back to the days of Egghead Software outlets.
Aside from the approval process, I think the lack of demos is the biggest problem with the App Store. As a user, I can waste time reading reviews and still get the decision wrong, or spend a few minutes actually using the app to quickly know whether it’s what I want. As a developer, I want as low a barrier as possible for people to try my apps, and I definitely want to avoid situations where someone buys the app, finds out it’s not what they thought it was, and I can’t even give them a refund.
Ironically, due to the closed architecture of iOS and the App Store, Apple is in position to offer the best try-before-you-buy experience. The OS could track and enforce the demo period, preventing piracy and making it standardized and easy for both developers and users. The app could simply ask the OS whether it’s running in demo mode. When the demo period is over, you could purchase in-app and continue, with all your data, without even having to re-launch. Instead, Apple is promoting lite apps, which pollute the App Store and offer a clumsy upgrade path.