I was not a app developer before, but a systems engineer with devops experience. But I learnt a lot about apple development, app store connect and essential became a app developer in a month. I don't think I can learn so quickly with other humans help.
If you lost access to AI would you be able to continue development on your app?
You might be surprised. In 2008, when the App Store first came out, I became an iPhone app developer after reading one book. I already knew C, so Objective C wasn't a big leap.
Between my own apps and consulting work, I had a pretty good side business. Like everything else though, those days didn't last forever. But there was a lot of easy money early on.