I'm going to make the case that it's actually the opposite. Rails might seem simpler out of the box, but this is all surface level. Rails is massive and extremely complex, especially its ORM, which encourages really bad database practices in my experience. And it doesn't have strong typing.

If you went head-to-head with Rails on a slightly complex project with say shadcn/ui, Convex DB, and TanStack Start, I guarantee you, the TypeScript app will be much simpler and give you more power than Rails, especially when building the UI. And to top it off, you will have strong typing everywhere -- from the DB schema to the URL routes.

And bonus, deployment is simple. ConvexDB already takes care of the backend and the frontend could be deployed to something like Cloudflare Pages.