I made the same realization two weeks ago. Posted about it here, where I rebuilt bare bones todoist with a habit tracker, goal setting and more within a few vibe coding sessions: https://news.ycombinator.com/item?id=46633092
I think that many existing apps with huge userbases will gradually lose users as the models become better and better. Their biggest advantage is that people don't like change, and thus having to e.g. export data from some tools etc. seems to be a hassle not worth $5 a month. But as the models get better and the quality of the output will match the quality of the established SaaS but tailor the whole thing to a single user with the ability to make any change they can imagine within minutes, and perhaps deploy to Hetzner and whatnot where they could host all of those apps for a single $5 instead, the exodus will accelerate.
On the other hand, new products will have a much harder time to gather a big userbase. Whenever I'll see a launch of a SaaS asking for $$$, the first question I'll ask myself will be how long it will take LLM to recreate it. And for most cases, I imagine that the time it will take to get 80% of what they have is a few vibe coding sessions (as most newcomers will probably have used LLM themselves to code it up).
> But as the models get better and the quality of the output will match the quality of the established SaaS but tailor the whole thing to a single user with the ability to make any change they can imagine within minutes, and perhaps deploy to Hetzner and whatnot where they could host all of those apps for a single $5 instead, the exodus will accelerate.
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.