Regarding desktop apps for both macOS and Windows:
In my case I sell 90% outside the Appstore and 10% in the AppStore (for the same app).
As Sam noted rightly, it does require more work (and that goes with limitations too) to make it acceptable for Apple.
Also, the verification process is something frustrating. Sometimes you get rejections for silly reasons that gets approved the next time you submit the same code. Figures.
Anyhow, if you are new to selling software, your best bet would be start outside the App Store or Windows Store.
What I do recommend is to use in-app buying. Don’t just point to your website for the payment procedure. Put that all in your app. Sales will be much better this way (mine sales doubled when I implemented this).
I use Paddle for this - it’s incredible easy to implement this in your app.