There'$ a rea$on that $o many people want to relea$e Apple app$. A $uperb rea$on.
It's a really lucrative market. People like to have access to customers that are used to paying a lot. One of the reasons those customers want to pay more, is that walled garden that HN members hate so much, but millions of people have no issue with (whether or not that's a good thing, is not for me to ponder. It just is).
99 bucks is peanuts. It does give you access to the entire suite of Apple tools. Anyone interested in shipping serious software, is likely to far exceed that, in the non-Apple (or Apple hardware) tools that they use to develop the software. Heck, your keyboard probably cost more than that. I remember that we used to pay Microsoft over $4,000 a year for their developer program.
Here's what Apple says about it[0]. That's what I usually do. I think someone else has shared the command line method. If it's a developer tool, then it would probably have a difficult time passing Apple's app review process, anyway, and that will really jangle your cortisol pipes.
[0] https://support.apple.com/guide/mac-help/open-a-mac-app-from...