How so? If I build a simple app that does its job and does it well, I don't need to work on it for 40 hours a week for the rest of my life. After the initial effort, you can put in almost no work, just periodic maintenance, and you can keep bringing in sales.
There are lots of opportunities like this. There is nothing morally or ethically questionable about this. It doesn't require you to over-inflate your prices. That is the power of software. The VC hyper-growth world is heavily focused on continuously changing your software, but that isn't a requirement (and in fact, is often not desirable to your customers).
If the market works as intended, someone will replicate your app and sell it cheaper, the price should eventually converge to the costs. And you might not agree, but I find it morally questionable [1] to run a business that pays good money for little work.
[1] There is of course more nuance to this then expressed here.
How does that make any sense? If you’ve built something that provides good value to people, more than they are paying for it, how can you believe that it is a morally questionable arrangement?
Imagine a tiny economy with two people. There is one guy that produces everything humans need and he can produce one day worth of supplies in four hours. But to keep his business running he depends on a piece of software that the other guy wrote, without it he could not produce anything. The other guy happily licenses his software for one day of supplies per day. Now the only thing he has to do besides enjoying all his supplies is to now and then spend an hour of work to maintain the software.