Personalized bedtime-story image generator

To all those "why should I use your app when I can build it myself?" posts, don't worry, you're not the target audience. This weekend I had a talk with a friend who works in a big corp and came to me: "Hey! I want your advice. I have this app idea that I want to build. What should I use to build it for both iOS and Android? How should I handle authentication? What about payment subscriptions?" It's a voice-to-text app that listens to his voice while he reads these bedtime stories for his daughter and generates an image with Nano Banana after he finishes a chapter. For all the books that don't have images in them, he wants to show his daughter a visual representation so she can better visualize the story. Really great idea! Right now he uses a workflow with Gemini that does this, but wants to monetize it and try to sell it to other parents. He never built an app before, but was super excited about this. Then another person at the table, who's a dev, never built an app in his life, said: "Why would I want to pay for your app when I can do this myself for free?" I was looking at my friend's face and he was a bit disappointed, but also tried to find reasons for the other guy to use/buy the app. I chuckled a bit. Then later that night I texted him saying to not worry about people like that dev and that he should start building the app. Especially since he has all this excitement and motivation. Just focus on the core functionality. Build that, refine it until happy, then worry about authentication, pricing, payments, etc. The more I spend time building my own apps, try to do marketing&sales, I realize we live in a bubble, where, yes, 1,000 people can build the same app, but they're not the target audience usually, and there are probably 100-1,000 other people on Earth that don't know programming/AI/storytelling/etc. to which you can sell this. Also, 99% of those saying they can build the app themselves, never do. If you find the idea and motivation to do build an app. Start, then figure the rest out. First few bets might not pay out. But the more you do it, the better you'll become at it and eventually can escape the 9-5 corporate world and work on something you truly believe in and enjoy. Scratch your own itch. Once you solved that. Productize it and see if other's are willing to pay for it. Start with your friends&family. Then move on to communities, subreddits, FB groups, social media, etc.