I do think you're vastly overestimating people's ability to write software, even with LLMs, and use it in production. The average computer user does not even use a computer as their primary computing device, they use a phone. The barrier to going from idea to phone app on iPhone or Android is relatively high.
Todo list apps, habit trackers, and the like are almost a special snowflake breed. Almost everyone has some different cross-section of needs they care about, and no app is perfect for each individual. So it's natural to say "is there something that matches what I want?" and then reach for tools to make that. The world is your oyster for todo list apps. Of course, the real issue comes from data sovereignty, trust, quality, things like that. When Apple launches a new device or a new iOS feature people want, you get to see which apps will actually implement the new features or which stagnate. They're a natural avenue for vibe coding since they're so particular.