That’s real fiction right there.

How did lambda manage to create this false idea that it makes everything instantly easy? If anything in many ways it makes things much more complex and harder and more expensive.

Serverless/Lambda is a deploy option, not an alternative to writing code. Take Laravel, for example - a popular framework that traditionally is deployed to servers, virtual or otherwise. Well not long ago, they released Laravel Vapor (https://vapor.laravel.com/), a deployment platform for your Laravel code. It takes some configuration, but you can generally take your Laravel app and run it on Lambda using Vapor super easily.

But you still gotta write that app.

That doesn't actually make it significantly easier. You still need a backend framework and database. It also doesn't change the frontend needs at all.

So, while serverless is not a silver bullet, I don’t know why you got downvoted, a combination of using serverless plus managed services can significantly lower the dev and ops overhead of a modern SaaS.