It makes random apps much less likely to be dangerous.

https://news.ycombinator.com/item?id=36086537 is an analogous case. When the primary provider of free domains names went away, there was a HUGE reduction in phishing websites. Those types would spin up thouands of sites on xyz, vip and similar TLDs faster than the white hats could whackamole them.

A domain going from $0 to $10 vastly curtailed that activity. You don't have to make something impossible, you just have to make it not cost effective to shot gun it.

Having "skin in the game" is a way to keep a community honest. Even darknet markets use bonding for vendors. Not to mention that in the case of Apple registration, it leaves a paper trail. Though I'd agree that the $99 for the privilege seems arbitrary.

You aren’t the center of other people’s lives. How is any old arbitrary user to know you’re not a con of a dev?

Software sales are contrived fiat exchange to give your code access to my hardware and userspace. Who the f are you?

- AppStore apps must be sandboxed.

- AppStore apps are reviewed by Apple.

- Apple can ban malicious app in AppStore.

- Apple checks binaries when you run them even they aren't from AppStore due to notarization.