> Who expects 'nice new features' from an app they already decided to buy?

I was just listing one more thing a developer who wasn't slacking might spend his time doing, that's all.

> Keeping the app compatible with new OS releases is necessary to keep sales going.

Relying on constant sales to new users sounds like a pyramid scheme. Software licenses don't wear out like shoes or become consumed like butter, with happy customers returning to buy more. Eventually, most of the people that need most apps have bought it and sales don't "keep going" more than a trickle, except for apps that are such mainstream hits that your new users are just "everyone who became old enough this month to get their first phone." And because the App Store has ruined organic discovery, paid apps rely almost exclusively on paying for installs either via Apple's ads or elsewhere. So, that eats a good part of each new sale's revenue right away.

Check the iOS top charts right now. For paid apps, the top-selling app is Shadowrocket, a rule-based proxy utility. How long until all developers who want a rule-based proxy utility have already paid the $3? If 100,000 developers buy that app, then that developer nets $210,000 pre-income-tax. About on par with a good corporate SWE job outside of FAANG. But that will slow down. There just aren't that many people who are looking for that. #2 is just a client of a subscription service for businesses. #3 is AnkiMobile Flashcards at $25. See, at that price I agree it can afford to never charge again. #4 is an ephemeral app for some art event in Portland so it doesn't need to be sustained. #5 is Procreate Pocket. I guess there are enough new aspiring artists appearing every day who can afford these apps (I think it's $13 for iPad).

> After a year, I don't think anyone is bothered if an app becomes unsupported for whatever reason.

Okay, so subscribe to the apps you use, and then immediately go in and turn off renewal in Settings -> (your Apple ID) -> Subscriptions. There. You now have a one-time purchase of an app which will stop working in a year - just like apps that have no recurring revenue stream do.

> This is an especially moot point now that most platform API upgrades are $1 of LLM work away.

I don't think you are a developer of serious iOS apps. Just the visual changes, that users expect apps to go along with, require major redesigns. People don't buy apps that look like they were designed in 2019.

You are right, I am not a developer of iOS apps, just a consumer. I buy apps where the feature set appeal to me, not promises. I will not jump through hoops like immediately cancelling a sub because the developer doesn't want to offer a one-time purchase.

I use several outdated apps, including Filmic Legacy etc, and am happy - I got what I paid for. Yes, they might stop working at some point. The only thing that bothers me is when the app is intentionally crippled or modified to "encourage" upgrades when it's working perfectly fine.