People on HN act like it’s so easy to reach all the addressable market.
Most software, especially in the world of mobile/desktop apps are usually feature-complete. The problem is that developers keeps redesigning and refactoring them to justify development, rather than focusing on another product or marketing efforts.
Free bug fixes are generally expected. But nobody forbids you from releasing v2 and charging for it again (for example with upgrade discount).
If no one new is buying your product and you are just supporting one time pay users, why would a developer be incentivized to keep doing updates?
When you buy a physical product, do you expect the company to stand behind the quality of their product by providing (limited) warranty and/or support, despite the fact that this won't bring the company any new income?
Nobody forbids you from selling your software with an asterisk that says "works on X.Y version of MacOS, future releases will require a new license".
And if no one new is buying your product, I think you need to ask yourself whether you have a sustainable business or a hobby.
Is it a “bug” when Apple releases a new OS/phone that either breaks backwards compatibility or does something like release the iPhone 5 and changes the form factor making your app look janky? This was when Apple released frameworks to allow phones of different sizes around 2012?
Or more recently should users expect a free upgrade when Apple deprecated 32 bit apps?
The Mac sees a lot less churn than iOS. But things do happen that cause apps not to work there. The most recent is that Electron was using a private API and all apps that used that version of Electron on Macs broke.