What's wrong with multiple monitors with macOS?

Yes, completely true. The Apple ecosystem is profitable for an app developer. iOS users are more likely to pay for purchases and subscriptions, making it easier to make a living on Apple's AppStore.

Also, Apple tends to treat developers much better than Google, which makes the AppStore the ideal place for an app developer who wants to make a living this way.

Hi, app developer here.

I know that subscriptions are frustrating but it's the only way to be on business this days.

For instance, let's say that you purchase a one-time fee that grants you lifetime access. 5 years after that you will continue to receive new features, new OSs adjustments to keep the app working, security patches, and changes to comply with store policies (which are becoming more and more strict every year btw).

Unfortunately it's impossible to be financially sustainable in the long term with one-time purchases only...

What I do is to try to keep the prices as lower as possible, arround 10-20$ per year, of which I receive less than half of it after taxes and store fees.

Even doing that is nearly impossible to survive, I don't really know how much time I will be able to be full time doing this :/