Why did everybody have to close down if costs are fully covered with a $2.99 subscription? I probably would have paid for reddit is fun at that price for myself and my wife. Assuming it stays ad free.
Everyone couldn't have. The more users you have using a app the higher the API hits, the higher the number of API hits the more you'd have the charge. So the more popular apps with the most users couldn't survive odd on just $2.99 a month and certainly not while continuing to update and upkeep that app (or those apps) because they wouldn't be making any money let alone enough to justify the work they'd be doing.
Additionally this isn't an ad free version of Reddit you'll be getting with this sub. It's still Reddit with ads.
Every user pays the same for the app, but the app pays an amount dependent on how much its users are browsing and posting. So if your users are all lurkers who open Reddit once a day, then you can make an easy profit charging a small fee. But if your core userbase are power posters and mods and people who spend every bathroom break on reddit, you'll lose money unless you charge a huge subscription.
The power users moving to Lemmy actually made these app subscriptions cheaper and more financially viable, because it brought down the activity level of their average user. If things had stayed the same, apps would be more expensive to run.
Funny enough, the more reddit dies, the more profitable third party apps get.
Yeah, I get that. But the devs know what their average API calls are per user, seems like they would have landed on those numbers here; less frequent users likely subsidize power users to some extent. Or, like reddit, they could price it dynamically based on your usage too.
But you also might be right that it's only affordable if ALL power users moved on. Probably fewer moved here than we'd hope/expect, but I'm sure it helped.